However, if you are doing to be running fetchmail or something similar to snarf your POP3 mailboxes, be very careful before re-injecting them into your own MTA - the messages will be missing the SMTP Envelope data, and this can cause problems if your address is not listed on the To field (i.e. mailing lists &c). You might end up posting them back out to someone else, rather than receiving them.
That's a great point - I am on a number of mailing lists.
Is there a simple way around this that you can offer?
Yep - don't ask fetchmail to re-inject messages via SMTP, instead ask it to drop them directly into your back-end mailstore - preferably via procmail (so you can ask procmail to spamfilter them)
I can't remember if SMTP delivery is fetchmail's default - I'm only saying "don't use it" without being very very sure it's the right thing to do :-)
Basically, email items living in a POP mailbox have been "delivered", and consist only only of the email headers and body - the envelope section has been lost. Most people starting off playing with an MTA for the first time do not realise the envelope ever existed :-) The envelope is what makes mailing list emails work ...
-jim
