Howard Spindel <howard(_at_)sci1(_dot_)com>:
Initially, I had a problem that was causing multiple copies of email to be
generated. I tracked this down to email that had multiple recipients on
the "To:" line. Some upstream ISP would generate a message with a
different message ID for each "To:" recipient but leave the "To:" header as
is, and when fetchmail used the "To:" header as the envelope address it
would generate duplicates.
How is this possible? By design, fetchmail never generates any mail other than
bounce and oversized messages. Where is it generating this duplicate?
I attempted to fix this problem by using an "Envelope X-Original-To"
command for fetchmail. That did fix the problem above, but created a new
problem. I do get one message for each X-Original-To recipient, but
sometimes the message-ID is the same. In multidrop mode fetchmail
suppresses messages with duplicate message-ID, and I can't find a switch to
turn that behavior off. So now instead of the original problem of
duplicate messages, only the first recipient on the "To:" line gets the
message and the second recipient is dropped.
When fetchmail sees adjacent messages with the same message-ID, it
only removes the second and subsequent duplicates. Either you are
misunderstanding what you are seeing or I am misunderstanding what I
am reading.
--
<a href="http://www.catb.org/~esr/";>Eric S. Raymond</a>