On 2017-02-12, at 15:56, Jesse 1 Robinson wrote:
>
> I cannot imagine any technical or policy reason for leaving that field blank.
> It has Omission written all over it. This problem affects multiple shops. If
> should be fixed at the source.
>
From RFC 822:
4.4.1. FROM / RESENT-FROM
This field contains the identity of the person(s) who wished
this message to be sent. The message-creation process should
default this field to be a single, authenticated machine
address, indicating the AGENT (person, system or process)
entering the message. If this is not done, the "Sender" field
MUST be present. If the "From" field IS defaulted this way,
the "Sender" field is optional and is redundant with the
"From" field. In all cases, addresses in the "From" field
must be machine-usable (addr-specs) and may not contain named
lists (groups).
4.4.2. SENDER / RESENT-SENDER
This field contains the authenticated identity of the AGENT
(person, system or process) that sends the message. It is
intended for use when the sender is not the author of the mes-
sage, or to indicate who among a group of authors actually
sent the message. If the contents of the "Sender" field would
be completely redundant with the "From" field, then the
"Sender" field need not be present and its use is discouraged
(though still legal). In particular, the "Sender" field MUST
be present if it is NOT the same as the "From" Field...
(Emphasis added, I hope.) And in RFC 2822:
... If the originator of the message can be indicated
by a single mailbox and the author and transmitter are identical, the
"Sender:" field SHOULD NOT be used.
So LISTSERV is following the recommendation
(... discouraged ... SHOULD NOT ... ) and your MTA seems to be deviating.
But in other contexts, experts have said that the venerable standards
invite threats and must be disobeyed.
-- gil
----------------------------------------------------------------------
For IBM-MAIN subscribe / signoff / archive access instructions,
send email to [email protected] with the message: INFO IBM-MAIN
