Sieve Email Filtering: Relational Extension
RFC 5231
| Document | Type |
RFC - Proposed Standard
(January 2008; No errata)
Obsoletes RFC 3431
|
|
|---|---|---|---|
| Last updated | 2015-10-14 | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Stream | WG state | (None) | |
| Document shepherd | No shepherd assigned | ||
| IESG | IESG state | RFC 5231 (Proposed Standard) | |
| Consensus Boilerplate | Unknown | ||
| Telechat date | |||
| Responsible AD | Scott Hollenbeck | ||
| Send notices to | alexey.melnikov@isode.com | ||
Network Working Group W. Segmuller
Request for Comments: 5231 B. Leiba
Obsoletes: 3431 IBM T.J. Watson Research Center
Category: Standards Track January 2008
Sieve Email Filtering: Relational Extension
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Abstract
This document describes the RELATIONAL extension to the Sieve mail
filtering language defined in RFC 3028. This extension extends
existing conditional tests in Sieve to allow relational operators.
In addition to testing their content, it also allows for testing of
the number of entities in header and envelope fields.
This document obsoletes RFC 3431.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions Used in This Document . . . . . . . . . . . . . . . 2
3. Comparators . . . . . . . . . . . . . . . . . . . . . . . . . . 2
4. Match Types . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4.1. Match Type VALUE . . . . . . . . . . . . . . . . . . . . . 3
4.2. Match Type COUNT . . . . . . . . . . . . . . . . . . . . . 3
5. Interaction with Other Sieve Actions . . . . . . . . . . . . . 4
6. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
7. Extended Example . . . . . . . . . . . . . . . . . . . . . . . 6
8. Changes since RFC 3431 . . . . . . . . . . . . . . . . . . . . 6
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 7
10. Security Considerations . . . . . . . . . . . . . . . . . . . . 7
11. Normative References . . . . . . . . . . . . . . . . . . . . . 7
Segmuller & Leiba Standards Track [Page 1]
RFC 5231 Sieve: Relational Extension January 2008
1. Introduction
The RELATIONAL extension to the Sieve mail filtering language [Sieve]
provides relational operators on the address, envelope, and header
tests. This extension also provides a way of counting the entities
in a message header or address field.
With this extension, the Sieve script may now determine if a field is
greater than or less than a value instead of just equivalent. One
use is for the x-priority field: move messages with a priority
greater than 3 to the "work on later" folder. Mail could also be
sorted by the from address. Those userids that start with 'a'-'m' go
to one folder, and the rest go to another folder.
The Sieve script can also determine the number of fields in the
header, or the number of addresses in a recipient field, for example,
whether there are more than 5 addresses in the to and cc fields.
The capability string associated with the extension defined in this
document is "relational".
2. Conventions Used in This Document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in BCP 14, RFC 2119.
Conventions for notations are as in [Sieve] section 1.1, including
the use of [Kwds] and the use of [ABNF].
3. Comparators
This document does not define any comparators or exempt any
comparators from the require clause. Any comparator used must be
treated as defined in [Sieve].
The "i;ascii-numeric" comparator, as defined in [RFC4790], MUST be
supported for any implementation of this extension. The comparator
"i;ascii-numeric" MUST support at least 32-bit unsigned integers.
Larger integers MAY be supported. Note: the "i;ascii-numeric"
comparator does not support negative numbers.
Segmuller & Leiba Standards Track [Page 2]
RFC 5231 Sieve: Relational Extension January 2008
4. Match Types
This document defines two new match types. They are the VALUE match
type and the COUNT match type.
The syntax is:
MATCH-TYPE =/ COUNT / VALUE
COUNT = ":count" relational-match
VALUE = ":value" relational-match
relational-match = DQUOTE
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