I alternatively use procmail as mailer beside the default mailer Mail.
I found that procmail only delivers mails if the user's mailbox is not empty,
i.e. it fails to create the mailbox file (reporting a lock failure). Because of
this, many mails have been lost ever since.
The system is FreeBSD + Sendmail + Procmail called via a .forward file.
The users' mailboxes are in /var/mail, which directory has the following
permissions:
drwxrwxr-x 3 root mail
The only solution I see is to make /var/mail word-writeable, when mails are
actually delivered, but I think this represents a very high security risk.
Is there a better workaround for this problem?
(If you received my letter with Subject: "Procmail stopped delivering mail to a
user", please disregard it, since I did not know then that the problem concerns
all users whose mailbox is empty)