[afnog] pop3 errors on fedora core 3 - LF not found on mailbox

[Brian Candler]

On Tue, Sep 13, 2005 at 09:04:22AM +0200, Dr Paulos Nyirenda wrote:
> Thanks for showing me formail. We did actually note that this error does go away for 
> an individual mailbox when we force recreation of the mailbox and then append old 
> mail to it.
> 
> However, this is not a scalable solution if one is managing kilos of mailboxes as we 
> do.

It sounds to me like your Red Hat mail delivery agent (sendmail?
sendmail+procmail?) and/or the Red Hat-supplied POP3 daemon are not
implementing mbox locking properly. I hope you're not storing your mbox
files on a remote server via NFS or Samba; that's almost bound to fail.

However, mbox files (/var/mail/user or /var/spool/mail/user) are not a
scalable solution in the first place. If you have someone who has clicked
'leave mail on server' and they have 10MB of mail in their mailbox, then
*every* POP3 login will require the POP3 server to open this file and read
it through from the start to the end, to divide it into individual messages.

> Is going back to RH9 the best solution?

I don't think so.

Firstly, you could install a more modern MTA (e.g. exim or postfix) and a
more modern POP3 server. If you install them from source you can make sure
they're compiled with the correct locking options. Or you can install from
RPMs and hope that the person who built the RPMs did so properly.

But if you're looking to fix scalability problems too, I would move over to
using Maildir storage, where every message is in a separate file, instead of
mbox. This is free of locking problems and scales a lot better. I have had
good experience with courier-imap's POP3/IMAP daemons (note they _only_ work
with Maildir, so there's no way to migrate to them while you're still using
mbox)

Regards,

Brian.