Running ispconfig 2.2.32 on CentOS 4.7 on several systems. On one only it seems that /var/mail/root accumulates with copies of messages that hit user mailboxes that have forwarding configured. The file grows until it is too large to be further written to at which point messages to users that have configured forwarding start bouncing with NDRs like this:
This is the Postfix program at host host.domain.
I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.
For further assistance, please send mail to <postmaster>
If you do so, please include this problem report. You can
delete your own text from the attached returned message.
The Postfix program
<firstname.lastname@example.org> (expanded from <original-recipient@domain>):
cannot access mailbox /var/mail/root for user root. error writing message:
File too large
Final-Recipient: rfc822; email@example.com
Original-Recipient: rfc822; original-recipient@domain
Diagnostic-Code: X-Postfix; cannot access mailbox /var/mail/root for user root.
error writing message: File too large