Hi,
Our internal mail server is a SuSE9.2 linux box running Fetchmail 6.2.5 
to collect mail from our ISP's catchall POP3 mailbox (single mailbox so 
we're using multi-drop) and then passes it to our internal Postfix 
(2.1.6) server. Our ISP doesn't add any form of envelope-to headers and 
so we've used the default (ie. not specified any envelope or -E setting 
in the .fetchmailrc file). Any email that Fetchmail collects that 
doesn't have a local Postfix mailbox is passed to the postmaster 
mailbox. We've had this working for 3 or 4 months with no problems at all.
However, in the last 2 weeks we've started to get an increasing number 
of, what appear to be valid emails, being dropped into the postmaster 
mailbox.
Initially I thought the problem was actually with our ISP as they run 
multiple MTAs and it seemed to be emails that had passed through two 
particular MTAs that were causing the problem. However, investigating 
further I now don't understand why our Fetchmail setup works correct at 
all. All of our mail actually has our catchall mailbox name as the first 
"Received" header that Fetchmail will see. Looking at it now, I would 
therefore expect Fetchmail to try to pass everything off to this 
catchall mailbox on our internal Postfix server - Postfix will see that 
it doesn't exist and therefore "dump" it to postmaster.......
......but this isn't happening, the vast majority of our emails do get 
routed and delivered correctly but I now think that for this to have 
happened I should have used the skip parameter in the envelope option 
(eg. envelope 2 Received) but I haven't. Does Fetchmail have some 
automatic logic that says if it's configured for multi-drop, it ignores 
the first "Received" header (because that will be to the catchall 
mailbox) and work from the second "Received" header without me having to 
have specified this in .fetchmailrc?
This does bring me back to my original problem though, as I can't see 
any difference at all in the headers that are on the misdirect emails as 
to the emails that work. I should perhaps add that I have read the 
multi-drop documentation and all of the emails that were causing the 
problem that made me look at this again are simple (ie. they're not from 
mailing lists, they're not bcc'ed - they're all to a single recipient 
with a valid "To" header).
Does anyone have any insight?
Thanks, David
--
Specialists in Wedding Stationery Design and Printing
www.libra-designs.co.uk <http://www.libra-designs.co.uk>