I have a setup consisting of postfix + maildrop, with maildir delivery and
quotas on maildirs (via maildirmake -q ).
While examining the logs, I noted that over-quota mails were deferred by
postfix, rather than bounced with an over-quota message.
Searching all over the net and through man-pages, maildrop (or rather
deliverquota) should return exit code 77 (EX_NOPERM) when over quota, and
postfix should bounce such messages.
However, I finally stumbled upon README.Debian, that says
--------------------------------
Patches
*******
The error code for errors on opening maildirs has been changed from
77 (EX_NOPERM) to 75 (temporary failure). See Debian bug 265399 for
a more thorough discussion of the reason for this patch.
--------------------------------
In deliver.C :
if ( deliver_maildir.MaildirOpen(mailbox, deliver_file,
maildrop.msgptr->MessageSize()) < 0)
throw 75;
In maildir.C :
...
merr << "maildrop: maildir over quota.\n";
return (-1);
...
So - MaildirOpen returns < 0 if account is over quota, as well as if the
disk-space is full.
A high-volume mailserver with possibly lot of "abusing" or forgetful
users, should not have over-quota mails deferred, as this may even cause
the server to run out of disk-space in the long run because of queue build
up.
A more fine-grained patch is thus required.
Regards,
Stefan
