Arnt Gulbrandsen wrote:
I'll bet it's a virus/spam filter. It's an ISP, so perhaps Spam
Assassin? If any of you have SA handy, please test it.
I have SpamAssassin. but only use its exit code, since it is known
to badly mangle messages (for a start, it changes CRLF to LF in
the message header but not in the message body).
I don't think that ISP does spam/virus checking on outbound mail.
More likely it may be some authentication program run in
conjunction with Exim:
X-Info: This message was accepted for relay by
smtp04.mrf.mail.rcn.net as the sender used SMTP authentication
X-Trace: P8Lg2xNl/q5fDAUYodEzlZwpyKDB79TknFKxJu+Prj0=
Now that was on a test message sent from me to me, which is certainly
not "for relay", but that's another chapter in the long sad story of
how some software authors and administrators fail to understand
certain key concepts.
Those fields were inserted between a Received field inserted by
smtp04.mrf.mail.rcn.net (Exim 3.35) and one inserted by
mx02.mrf.mail.rcn.net (also Exim 3.35). In the case of the
original list message under discussion, the equivalent fields
appear between Received fields inserted by smtp02.mrf.mail.rcn.net
and a list mailbox' MX host, above.proper.com, which seems to be
running sendmail.