Error while writing to "/var/spool/mail/matthias"

Hello
Yesterday I've been fetching around 1500 emails via pop3 to a local mbox using
fetchmail and procmail to sort them.
Today I got several mails from people who got bounces from the postfix running
on the same machine i fetched the mails to with these error message in it:
Diagnostic-Code: X-Postfix; can't create user output file.
   Command output: procmail: Error while writing to "/var/spool/mail/matthias"

Now, I've grep'ed through the procmail source to try and see where this error
comes from, but all I found was opening dev/null and the logfile.
Does someone here know why this occurs or has an idea what might cause this?

Thanks in advance,
 Benjamin


____________________________________________________________
procmail mailing list   Procmail homepage: http://www.procmail.org/
procmail(_at_)lists(_dot_)RWTH-Aachen(_dot_)DE
http://MailMan.RWTH-Aachen.DE/mailman/listinfo/procmail