Network Working Group                         Greg Vaudreuil
          Internet Draft                             Tigon Corporation
          Expires: 10/25/94                             April 25, 1994
                               MIME/ESMTP Profile for
                                   Voice Messaging
                1) Fix Bibliography, Make References in Text
          Status of this Memo
          This document is an Internet Draft.  Internet Drafts are working
          documents of the Internet Engineering Task Force (IETF), its
          Areas, and its Working Groups.  Note that other groups may also
          distribute working documents as Internet Drafts.
          Internet Drafts are valid for a maximum of six months and may be
          updated, replaced, or obsoleted by other documents at any time.
          It is inappropriate to use Internet Drafts as reference material
          or to cite them other than as a "work in progress".
          A class of special purpose computers have evolved to provide
          voice messaging services.  These machines generally interface to
          a telephone switch and provide call answering and voice messaging
          services.  Traditionally messages sent to a non-local machine are
          transported using analog networking protocols based on DTMF
          signaling and analog voice playback.  As the demand for
          networking increases, there is a need for a standard high quality
          digital protocol to interconnect these machines.
          The following document is a profile of the Internet standard MIME
          and EXMTP protocols for use as a digital voice networking
          protocol.  This profile is based on an earlier effort in the
          Audio Message Interchange Specification (AMIS) group to define a
          voice messaging protocol based on X.400 technology.  This
          protocol is intended to satisfy the user requirements statement
          from that earlier work with the industry standard ESMTP/MIME mail
          protocol infrastructures already used within corporate internets.
          This profile will be called the voice profile in this document.
          2.Scope and Design Goals
          MIME is the Internet multipurpose, multimedia messaging standard.
          This document explicitly recognizes these capabilities and
          provides a mechanism for the exchange of various messaging
          technologies including voice and facsimile.
          It is not a goal to make the interoperation of the earlier X.400
          based AMIS-Digital and this profile possible by the use of a
          standard X.400 to MIME gateway.  While the message encodings and
          messages semantics are similar, the addressing and routing are
          not.  The X.400 based AMIS-Digital addressing format is
          Internet Draft       Voice Profile       April 25, 1994
          sufficiently customized that it cannot be mapped to the RFC 822
          mail format in the standard manner. The voice profile is
          necessarily incompatible because it is intended to use the
          standard TCP/IP mail addressing formats.
          It is a goal of this effort to make as few protocol changes to
          the existing Internet mail protocols as possible while satisfying
          the user requirements for Voice Networking.  This goal is
          motivated by the desire to increase the accessibility to digital
          messaging by enabling the use of proven existing networking
          software for rapid development.  Using the native capabilities of
          the internet mail system most user requirements listed in the
          appendix can be met.
          This specification is intended for use on a TCP/IP network.
          While it is possible to use these protocols for simple point to
          point networking, the specification is robust enough to be used
          in an environment such as the global Internet with installed base
          gateways which do not understand MIME.  It is expected that a
          messaging system will be managed by a system administrator who
          can perform TCP/IP network configuration.  When using facsimile
          or multiple voice encodings, it is expected that the system
          administrator will maintain a list of the capabilities of the
          networked mail machines to reduce the sending of undeliverable
          messages due to lack of feature support.
          This specification is a profile of the relevant TCP/IP Internet
          protocols.  These technologies, as well as the specifications for
          the internet mail protocols are defined in the Request for
          Comment (RFC) document series.  This series documents the
          standards as well as the lore of the TCP/IP protocol suite.  This
          document should be read with the following RFC documents: RFC
          821, the Simple Mail Transport Protocol, RFC 822, the Standard
          for the format of ARPA Internet Messages, RFC 1521 and RFC 1522,
          the Multipurpose Internet Mail Extensions, RFC 1425 and RFC 1427,
          Extensions to the SMTP protocol (ESMTP), and RFC 882 and RFC 883,
          the Domain Name System.  Where additional functionality is
          needed, it will be defined in this document or in an appendix.
          3.Protocol Restrictions
          The number of recipients per message is not limited by this
          protocol.  Where possible implementations should not restrict the
          number of recipients that can be received in a single message.
          The maximum message length is not limited by this protocol.
          Implementors should understand that some machines will be unable
          to accept excessively long messages.  A mechanism is defined in
          the RFC 1425 ESMTP extensions to declare the maximum message size
          supported. (Units are in bytes, not minutes which can vary by
          encoding format.)
          4.Framework for the voice profile
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          This document specifies a profile of the TCP/IP multi-media
          messaging protocols for use by special purpose voice processing
          platforms.  These platforms are not general purpose computers and
          often do not have facilities normally associated with an Internet
          Email capable computer.
          The following are typical restrictions imposed by a voice
          messaging platform.
          1) Text messages are not normally received and often cannot be
             displayed or viewed in the normal fashion.  They can be
             processed only via advanced text-to-speech or text-to-fax
             features not currently present in these machines.
          2) Voice mail machines act as an integrated Message Transfer
             Agent and a User Agent.  The VM is responsible for final
             delivery and there is no forwarding of messages.  RFC 822
             header fields have limited use in the context of the simple
             messaging features currently deployed.
          3) Voice mail message stores are generally not capable of
             preserving the full semantics of an Internet Message.  As
             such, use of a VM for general message forwarding and
             gatewaying is not supported.  Storage of Received lines and
             Message-ID may be be limited.
          4) Internet style mailing lists are not generally supported.
             Distribution lists are implemented as local alias lists.
          5) There is generally no human operator.  Error reports must be
             machine parsable so helpful responses can be given to users
             whose only access mechanism is voice.
          6) The system user names are limited to 16 or fewer numeric
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          5.Message Format Profile
          The voice profile was written to be based on and be consistent
          with the TCP/IP Protocol Suite as amended to support specific
          services not provided in the TCP/IP protocol suite.  This section
          is intended to be an overview of the necessary protocols and a
          profile of the applicable protocols as applied to the voice
          messaging environment.
          5.1. Message Addressing Formats
          RFC 822 and SMTP addressing use the domain name system.  This
          naming system has two components, the local part, used for
          username or mailbox identification and the host part, used for
          machine or node identification.  These two components are
          separated by the commercial @ symbol.
          The local part is an ASCII string uniquely identifying a mailbox
          on a destination system.  It is required to be unique with the
          system of networked voice mail machines.  The local part is
          defined to be a printable string containing the mailbox number of
          the originator or a recipient.  Administration of this number
          space is expected to be conformant with national or corporate
          telephone numbering plans.
          The domain part of the address is a hierarchical global name for
          all machines.  In the domain name system, a name is registered
          with the Internet Assigned Number Authority (IANA). The IANA may
          delegate the management of a branch of the naming space to be
          administered by a company or service provider.  For participation
          in the international Internet network, or for integration within
          a corporate internet, each voice mail (VM) machine is required to
          be given a unique domain name.
          For example, a compliant message may be
          It should be noted that while the example mailbox address is
          based on the North American Numbering Plan any other corporate
          numbering plan can be used.  The use of the domain naming system
          should be transparent to the user.  It is the responsibility of
          the VM to translate the dialed address to the fully qualified
          domain name (FQDN).  The mapping of dialed address to VM
          destination is generally accomplished through implementation
          specific means.
          Mapping of the FQDN to a specific network destination is
          generally performed by the Domain Name System.  For networks with
          a small number of machines, the use of a locally maintained host
          table database can be used as a simpler alternative.
          Special addresses are provided for compatibility with the
          conventions of the Internet mail system and to facilitate
          testing.  These addresses do not use numeric local addresses both
          to conform to current Internet practice and to avoid conflict
          with existing numeric addressing plans.
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                      By convention, a special mailbox named postmaster
                      should exist on all systems.  This address is used
                      for diagnostics and should be checked regularly by
                      the system manager. This mailbox is particularly
                      likely to receive text messages. This is not normal
                      on a voice processing platform and the specific
                      handling of these messages is up to specific
                      A special mailbox name named "loopback" should be
                      designated for loopback testing.  All messages sent
                      to this mailbox must be returned back to the sender
                      address.  Because VMs do not use alpha-numeric
                      addresses, this will not conflict with any internal
                      numbering plan. Internal to VM, a specific numeric
                      address for DTMF entry can be mapped to "loopback".
                      Note that the loopback address can be abused to
                      route messages through a third party VM to avoid
                      toll charges.  It is recommended that the loopback
                      feature be disabled except when testing the
                      networking between machines.
          5.2. Message Header Fields
          Internet messages contain a header information block.  This
          header block contains information required to identify the
          sender, the list of recipients, the message send time and other
          information intended for user presentation.  Except for
          specialized gateway and mailing list cases,  headers are not used
          to indicate delivery options for the transport of messages.
          RFC 822 defines a set of standard message header fields.  This
          set is extended in several RFCs.
          Note that the specific order of header lines is not specified.
          The order cannot be expected to be preserved when sent through
          intermediate gateways.  The following header fields must be
                      The originators fully qualified domain address.
                      (This is a mailbox number followed by the fully
                      qualified domain name.)  The user listed in this
                      field should be presented in the voice message
                      envelope as the originator of the message.
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                      The recipient's fully qualified domain address.
                      There may be one or more To: fields in any message.
                      All recipients of a message must be listed in To
                      lines except when a recipient is specifically
                      intended to receive a blind carbon copy.  Note that
                      many voice mail systems have no facilities for
                      storing or for reporting to the recipient the list
                      of recipients.  These systems will generally discard
                      these headers when received.
                      It is recommended that all messages contain the text
                      personal name of the sender and the personal name of
                      the recipient in comment fields if available.
                      Additional recipients fully qualified domain
                      address.  This field has no meaning beyond "To:" in
                      a VM and is not to be generated by an conforming
                      implementation. It is included for processing by the
                      receiver for compatibility with general Internet
                      mail agents which may not restrict the use of this
                      If the VM supports the reporting of multiple
                      recipients, all names in the To: and Cc: fields
                      should be reported.
                      The date, time, and time zone the message was
                      composed by the originator or the time specified by
                      the originator if the message is scheduled for
                      delayed delivery.  Conforming implementations must
                      be able to convert RFC 822 date and time stamps into
                      local time.  If the VM reports message sent time,
                      the value in this field should be used, not the time
                      the message was received at the destination system.
                      Example:  Wed, 28 Jul 93 10:08:49 PDT
                      The actual address of the originator if the message
                      is sent by an agent on behalf of the author
                      indicated in the From: field..  This field is not to
                      be generated by an conforming implementation. It is
                      included for processing by the receiver for
                      compatibility with general internet mail software
                      which may generate this header.
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                      The sender field often contains the name of a
                      Internet style mailing list administrator and is the
                      address to report errors in the event that the ESMTP
                      MAIL FROM address is not available.  While it may
                      not be possible to save this information in some
                      Voice Mail machines, discarding this information or
                      the SMTP MAIL FROM address will make it difficuly to
                      send a error message to the proper destination.
                      A unique per-message identifier must be included by
                      the originator for every message. Conforming systems
                      must use an identifier constructed by concatenating
                      with a dash the sending VMs FQDN and a 8 digit
                      serial message number which is unique on the sending
                      system. This identifier will be used for tracking,
                      auditing, and returning delivery reports.
                      Received headers are special purpose trace
                      information added to the beginning of a RFC 822
                      message by message transport agents.  This is the
                      only header which is permitted to be added by a MTA.
                      These headers are useful for debugging when using an
                      ASCII message reader or a header parsing tool. A
                      conforming system must add received headers when
                      acting as a gateway.  These headers must not be
                      removed by a system when acting as a gateway.  These
                      headers may be ignored or deleted when the message
                      is received at the final destination.
          MIME Version
                      The Mime-Version: 1.0 header indicates that the
                      message is conformant to the RFC 1341 message format
                      specification.  It must be present in any conforming
                      message. From RFC 1341
                      The content-type header declares the type of content
                      enclosed in the message.  One of the allowable
                      contents is multipart, a mechanism for bundling
                      several message components into a single message.
                      The allowable contents are specified in the next
                      section.  From RFC 1341
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                      Because Internet mail was initially specified to
                      carry only 7 bit US-ASCII text, it may be necessary
                      to encode voice and fax data into a representation
                      suitable for this environment.  The content-
                      transfer-encoding header describes this
                      transformation if needed. From RFC 1341
                      This field indicates the requested privacy. If this
                      field exists, regardless of the selected case
                      insensitive value "Personal" or "Private". If no
                      privacy is requested, this field is omitted.
                      If a sensitivity header is present in the message,
                      an conformant system is prohibited from forwarding
                      this message.  If the receiving system does not
                      support privacy, and the sensitivity is one of
                      "Personal" or "Private", the message must be
                      returned to the sender with an appropriate error
                      message indicating that privacy could not be assured
                      and the message was not delivered.
                      The specific privacy values do not need to be
                      offered individually to users, but can be set on a
                      system wide basis.
                      This field indicates the requested priority to be
                      given by the receiving system.  The case insensitive
                      values "low", "normal" and "high" are specified.  If
                      no special importance is requested, this header may
                      be omitted and the value assumed to be "normal".
                      This field can be used to order messages in a
                      recipients mailbox and is equivalent to the AMIS
                      Priority indication.
          5.3. Message Content Types
          MIME is a general purpose message body format that is extensible
          to carry a wide range of body parts.  The basic protocol is
          described in [RFC-MIME]. MIME also provides for encoding binary
          data in such a manner that it can be transported over the 7 bit
          text oriented SMTP protocol.  This transport encoding is
          independent of the audio encoding that is designed to generate a
          binary object.
          MIME defined two transport encoding mechanisms, one designed for
          text-like data, "Quoted-Printable", and one for arbitrary binary
          data, "Base-64".  While base-64 is dramatically more efficient
          for audio data, both will work.  A null encoding of "Binary" was
          specified for use in an environment where binary transport is
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          An implementation in conformance with this profile is required to
          send audio data encoded as binary where binary message transport
          is available.  Where binary transport is not available,
          implementations must encode the message as Base-64.  As required
          by MIME, and to preserve interoperability with the fullest range
          of possible devices, the detection of and decoding of quoted-
          printable must also be supported.
          The following content-types are profiled.  Note that each of
          these contents can be sent individually in a message or wrapped
          in a multipart message to send multi-segment messages.
          The following content types are identified for use with this
                      Audio/Basic was defined as 64Kbps u-law in the base
                      MIME protocol document. Support of Audio/Basic is
                      recommended for compatibility with current Internet
                      workstations but not required for conformance with
                      this profile.
          Message/RFC822 (REQUIRED)
                      MIME requires support of the Message/RFC822 message
                      encapsulation body part.  This body part is used in
                      the internet for forwarding complete messages within
                      a multipart/mixed message.  Processing of this body
                      part entails trivial processing to unencapsulate-
                      encapsulate the message.  It is not to be sent by a
                      system conformant to this profile but must be
                      accepted for conformance with basic MIME.
          Text/Plain (REQUIRED)
                      MIME requires support of the basic text/plain
                      content type.  This content has no applicability
                      within the voice messaging environment and should
                      not be sent.  Behavior upon receipt of such a type
                      is dependent upon the platform and interpretation of
                      such a part is left as an implementation decision.
                      Options include dropping the body part and sending a
                      delivery report indicating the lack of support,
                      text-to-speech, and text-to-fax support.
          Multipart/Mixed (REQUIRED)
                      MIME provides the facilities for enclosing several
                      body parts in a single message. Multipart/Mixed may
                      be used for sending multi-segment voice messages,
                      that is, to preserve across the network the
                      distinction between an annotation and a forwarded
                      message. Systems are permitted to collapse such a
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                      multi-segnemt message into a single segment if they
                      are not supported on the receiving machine.
          Text/Signature (RECOMMENDED)
                      Text/Signature provides a mechanism for the sending
                      of per-user directory information including the
                      spoken name and the supported mailbox capabilities.
                      When used with a caching mechanism, basic directory
                      services with entries for commonly used entries can
                      be maintained.  This body part is to be used to
                      support spoken name confirmation and ASCII name for
                      dial-by-name applications.  The Text/Signature can
                      be included with a message using the multipart/mixed
                      constructor type.  From <draft-vaudreuil-sig-02.txt
          Message/Notification (REQUIRED)
                      This new MIME body part is used for sending delivery
                      status notifications. From <draft-ietf-notary-
          Multipart/Notification (REQUIRED)
                      The Multipart/Delivery-Notification is used for
                      enclosing a text/delivery-notification body part and
                      any returned message content.  This body type is a
                      companion to and is defined with the text/delivery-
                      report.  Systems may optionally send a text
          Audio/ADPCM (REQUIRED)
                      CCITT Draft Recommendation G.721 describes the
                      algorithm recommended for conversion of a 64 KB/s A-
                      law or  -law PCM channel to and from a 32 KB/s
                      channel.  The conversion is applied to the PCM
                      stream using an Adaptive Differential Pulse Code
                      Modulation (ADPCM) transcoding technique. This
                      algorithm will be registered with the Internet
                      Assigned Numbers Authority for MIME use under the
                      name Audio/ADPCM.
                      ADPCM is widely available. Support of Audio/ADPCM is
                      required for conformance with this profile.
          Proprietary Voice Formats (OPTIONAL)
                      Proprietary voice encoding formats are supported
                      under this profile provided a unique identifier is
                      registered with the IANA prior to use.
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                      Note that use of proprietary encodings reduces
                      interoperability in the absence of system
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          6.Message Transport Protocol (ESMTP)
          Messages are transported using the Internet Extended Simple Mail
          Transport Protocol.  This protocol is used to send messages
          between voice mail machines.  All information required for proper
          delivery of the message is included in the ESMTP dialog.  This
          information, including the sender and recipient addresses is
          commonly referred to as the message "envelope".  This information
          is equivalent to the message control block in many analog voice
          networking protocols.
          ESMTP is a general purpose messaging protocol, designed both to
          send mail and to allow terminal console messaging.  SMTP was
          originally created for the exchange of US-ASCII 7 bit text
          messages.  Binary and 8 bit text messages have traditionally been
          transported by encoding the messages into a 7 bit text-like form.
          RFC 1425 was recently published and formalized an extension
          mechanism for SMTP and subsequent RFCs have defined 8 bit text
          networking and extensions to permit the declaration of message
          size for the efficient transmission of large messages such as
          multi-minute voice mail.
          Binary transport is currently under development in the IETF.
          When completed, the binary extensions to ESMTP will be required
          for conformance with this profile.  The current version of this
          protocol is available in the public Internet Drafts directories
          in the file <draft-ietf-vaudreuil-binary-02.txt>
          A command streaming extension for high performance message
          transmission is under development in the IETF.  This extension
          reduced the number of round trip packet exchanges and makes it
          possible to validate all recipient addresses in one operation.
          This extension is optional but recommended.  This document is
          available in the public Internet Draft directories in the file
          The following ESMTP commands may be supported.
          6.1. ESMTP Commands
          HELO (REQUIRED)
                      Base SMTP greeting and identification of sender.
                      This is not to be sent by conforming systems unless
                      the more capable EHLO command is not accepted.  It
                      is included for compatibility with general SMTP
                      Originating mailbox.  This address contains the
                      mailbox to which errors should be sent.  This
                      address may not be the same as the message sender
                      listed in the message header fields in the event
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                      that the message was gatewayed or sent to a Internet
                      style mailing list.
          RCPT TO (REQUIRED)
                      Recipients Mailbox.  This field contains only the
                      addresses to which the message should be delivered
                      for this transaction.  In the event that multiple
                      transport connections to multiple destination
                      machines are required for the same message, this
                      list may not match the list of recipients in the
                      message header.
          DATA (REQUIRED)
                      The command to initiate the transfer of message
                      data.  This command is required to be supported but
                      should only be used in the event the binary mode
                      command BDAT is not supported.
                      The turn command requests a change-of-roles, that
                      is, the client which opened the connection offers to
                      assume the role of server for any mail the remote
                      machine may which to send.  This is useful to poll
                      for messages.
                      (Note the security implications of using the turn
                      command to fetch mail queued for another
                      destination.  This is possible due the lack of
                      authentication of the sending VM by the protocol)
          QUIT (REQUIRED)
                      QUIT requests that the connection be closed.  If
                      accepted, the remote machine will reset and close
                      the connection.
          RSET (REQUIRED)
                      Reset the connection to the initial state.
          VRFY (OPTIONAL)
                      The VRFY command requests verification that the
                      listed recipient is reachable by this node.  While
                      this functionality is also included in the RCPT TO
                      command, VRFY allows the query without beginning a
                      mail transfer transaction.  This command is useful
                      for debugging and tracing problems.
                      (Note that the implementation may simplify the
                      guessing of a recipients mailbox or automated sweeps
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                      for valid mailbox addresses resupting in a possible
                      reduction in privacy.  Various implementation
                      techniques may be used to reduce the threat such as
                      limiting the number of queries per session.)
          EHLO (REQUIRED)
                      EHLO is an enhanced mail greeting which enables a
                      server to announce the support for extended
                      messaging options.  The extended messaging modes are
                      discussed in a later section.
          BDAT (REQUIRED)
                      Initiate binary data transmission
                      The BDAT command is an alternative to the earlier
                      DATA command.  The BDAT command does not require
                      encoding voice data into 7 bit line limited formats.
          All other commands must be recognized and an appropriate error
          code returned if not supported.
          6.2. ESMTP Keywords
          STREAMING (Optional)
                      The streaming keyword indicates the ability of the
                      receiving SMTP to accept pipelined SMTP commands.
                      (from Internet Draft <draft-freed-streaming-01.txt>
          SIZE (Required)
                      The size indication provides a mechanism by which
                      the receiving SMTP can indicate the maximum size
                      message supported.  (from RFC 1427)
          CHUNKING (Required)
                      The chunking keyword indicates that the receiver
                      will support the high performance binary transport
                      mode. - Note that CHUNKING can be used with any
                      message format and does not imply support for binary
                      encoded messages.  (from Internet-Draft <draft-
          BINARYMIME (Required)
                      The binarymime keyword indicates that the receiver
                      SMTP can accept binary encoded MIME messages.  Note
                      that CHUNKING mode must be supported for this
                      option, but that CHUNKING does not mean that binary
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                      messages can be supported.  (from Internet-Draft
          6.3. ESMTP Parameters - MAIL FROM
          BINARYMIME  The binarymime parameter indicates that the current
                      message is a binary encoded MIME messages.
          6.4. ESMTP Parameters - RCPT TO
          NOTIFY      The notify parameter specifies the conditions under
                      which a delivery report should be sent. From <draft-
          RET         The ret parameter indicates whether the content of
                      the message should be returned. From <draft-ietf-
          PRIORITY    This parameter indicates the requested priority to
                      be given by the transmission network. From <draft-
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          7.Management Protocols
          The Internet protocols provide a mechanism for the management of
          voice mail machines, from the management of the physical network
          through the management of the message queues.  SNMP should be
          supported on a compliant message machine.
          The digital interface to the VM and the TCP/IP protocols should
          be managed.  MIB II provides basic statistics and reporting of
          the TCP/IP protocol performance and statistics.  Media specific
          MIBS are available for X.25, Ethernet, FDDI, Token Ring, Frame
          Relay and other network technologies.  This MIB provides
          necessary information to diagnose faulty hardware, overloaded
          network conditions, and excessive traffic conditions from a
          remote management station.
          Management of the machine resources and message queue monitoring
          based on the host MIB and the Message and Directory MIB is
          recommended but not required for conformance with this profile.
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          [MIME]Borenstein, N., and N. Freed, "Multipurpose Internet Mail
          Extensions", RFC 1521, Bellcore, Innosoft, Sept 1993.
          [MSG] Crocker, D., "Standard for the Format of ARPA Internet
          Text Messages", STD 11, RFC 822, UDEL, August 1982.
          3.    Freed, N., "SMTP Service Extension for Command Pipelining"
          Internet Draft Work in Progress - 10/19/93.
          4.    Klensin, J., Freed, N., Rose, M., Stefferud, E., and D.
          Crocker, "SMTP Service Extensions" RFC 1425, United Nations
          University, Innosoft International, Inc., Dover Beach Consulting,
          Inc., Network Management Associates, Inc., The Branch Office,
          February 1993.
          5.    Klensin, J, Freed, N., Moore, K, "SMTP Service Extensions
          for Message Size Declaration" RFC 1427,  United Nations
          University, Innosoft International, Inc., Inc., February 1993.
          February 1993
          6.    Klensin, J., Freed, N., Rose, M., Stefferud, E., D.
          Crocker, "SMTP Service Extension for 8bit-MIMEtransport" RFC
          1426, United Nations University, Innosoft International, Inc.,
          Dover Beach Consulting, Inc., Network Management Associates,
          Inc., The Branch Office, February 1993.
          7.    Mockapetris, P.,"Domain names - implementation and
          specification", RFC1035, Nov 1987.
          8.    Mockapetris, P.,"Domain names - concepts and facilities",
          RFC 1034, Nov 1987.
          9.    Postel, J., "Simple Mail Transfer Protocol", STD 10, RFC
          821, USC/Information Sciences Institute, August 1982.
          10.   Vaudreuil, G., "Text/Signature", Internet Draft Work-in-
          Progress - 11/22/93.
          11.   Vaudreuil, G., "SMTP Service Extensions for Transmission
          of Large and Binary MIME Messages", Internet Draft Work-in-
          Progress - 11/10/93.
          12.   Vaudreuil, G., "An Extensible Message Format for Delivery
          Status Notifications", Internet Draft Work-in-Progress -
          9.Security Consideration
          Vaudreuil             Expires 10/25/94             [Page 17]

          Internet Draft       Voice Profile       April 25, 1994
          10.  Author's Address
          Gregory M. Vaudreuil
          The Tigon Corporation
          17080 Dallas Parkway
          Dallas, TX 75248-1905

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          Internet Draft       Voice Profile       April 25, 1994
          11.  Appendix - Example Voice Message
          The following message is a full featured, all options enabled
          message. It is addressed to two receipients. The message includes
          the senders spoken name and a short speach segment.  The message
          is marked as important and private.  read receipts and positive
          delivery acknowledgement are requested.
          Date: Mon, 26 Aug 93 10:20:20 CST
          MIME-Version: 1.0  (Voice Profile Version 1)
          Content-type: Multipart/Mixed; Boundary = "MessageBoundary"
          Content-Transfer-Encoding: 7bit
          Return-content: Full
          Sensitivity: Private-if-Possible
          Importance: High
          Content-type: Text/Signature
          Name:         User, Joe, R. (Joe Random User)
          SpokenName:   lslfdslsertiflkTfpgkTportrpkTpfgTpoiTpssdasddasdasd
                       (This is the base-64 encoded spoken name)
          Capabilities: Audio/Basic, Audio/ADPCM, Application/Signature,
          Content-type: Audio/ADPCM
          Content-Transfer-Encoding: Base-64
          (This is a sample of the base-64 message data) fgdhgdfgd
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Internet Draft       Voice Profile       April 25, 1994
          12.  Appendix - Example ESMTP Transaction
          The following ESMTP transaction represents the successful sending
          of a simple message to a system which does not support extended
          transport modes.  Non-ESMTP protocol events are noted in Italics.
          ESMTP commands and significant significant replies are in Bold.
          Except for the replies to the EHLO command, the text following
          the reply code is optional.
          Sender                                    Receipient
                                                    Wait for TCP
          Initiate TCP Connection to Port 25
                                                    Accept TCP
                                                    220 ready
                                                    250 SIZE 100000
          MAIL FROM: <>
                                                    250 Address OK
          RCPT TO: <>
                                                    250 Address OK
                                                    354 Send Message
          MIME-Version: 1.0
          Content-Type: Audio/ADPCM
          Content-Transfer-Encoding: Base64
          JFsdfjlkdjflkjsd lfflskjslkfjslfkjlsk
                                                    250 OK
                                                    250 Goodby
                                                    Receiver closes TCP