%% You should probably cite rfc8494 instead of this I-D.
@techreport{melnikov-email-over-pmul-05,
    number =    {draft-melnikov-email-over-pmul-05},
    type =      {Internet-Draft},
    institution =   {Internet Engineering Task Force},
    publisher = {Internet Engineering Task Force},
    note =      {Work in Progress},
    url =       {https://datatracker.ietf.org/doc/draft-melnikov-email-over-pmul/05/},
    author =    {David Wilson and Alexey Melnikov},
    title =     {{Multicast Email (MULE) over ACP 142}},
    pagetotal = 16,
    year =      2018,
    month =     jun,
    day =       1,
    abstract =  {ACP 142 defines P\_MUL, which is a protocol for reliable multicast suitable for bandwidth constrained and delayed acknowledgement (Emissions Control or "EMCON") environments running over UDP. This document is a specification of the basic protocol for electronic mail transfer over ACP 142 to enable MTA to MTA transfer. It explains how MULE can be used in conjunction with Simple Mail Transfer Protocol (RFC 5321), including some common SMTP extensions, to provide an alternate MTA to MTA transfer mechanism.},
}