[pkg-fetchmail-maint] Bug#494418: fetchmail loses mail when From address malformed

[Matthias Andree]

Hi Bruce,

it's not fetchmail losing mail, but Exim rejecting it.

If fetchmail made up addresses, that in itself would constitute data
corruption, i. e. a grave bug. I'm not going to introduce grave bugs to
bypass configuration issues in other software.
So that's not going to happen.

Fetchmail also cannot make up addresses since it would then have to find
SOME domain where the mail originated from and inevitably misattribute
the mail origin - but how? {fetchmail,mailer-daemon}@localhost is not
the origin and I refuse to pretend the message originated locally.
Your mail log hints to the broken messages being spam, and you
definitely do not want spam misattributed to some other domain, but not
any other mail either.

That's the second reason why it's not going to happen.
Keeping the message is not an option either since you want fetched
messages flushed and there is no way fetchmail can ever make progress
and discarding it is the right way.
This behaviour however contradicts documentation, so there are open bug
reports:
- <https://bugzilla.novell.com/show_bug.cgi?id=246829>
- <http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=471283>

So the solution alternatives are:

1 - make exim accept such mail at least from localhost and/or via local
    loopback interface

2 - use an MDA and bypass Exim and all the filtering it might do.

I'd suggest to close this bug (it's a WONTFIX for me) and check #471283
regularly.

-- 
Matthias Andree