This mostly happens when the mail account using autoreponder gets lot of spam mail, and as many of these spam mails use bogus From addresses, this account also recieves many mailer-daemon responses while replying to these bogus email addresses
Since the autoresponder does reply to mailer-daemon addresses (system mail accounts), it could create a mail loop if the other mail server does not correctly handle mail for system mail address and tries to bounce them back.
We have modified the autoresponder in WEBppliance Pro 3.5.18 to reject (not respond to) mail from system mail accounts like mailer-daemon and also made it more resistent to mail loops.
This issue has been resolved in WEBppliance Pro 3.5.18, Please refer to the Release Notes for more details.
WEBppliance Pro users prior to 3.5.18 are strongly advised to upgrade to 3.5.18 (or higher) to resolve this issue.
Given below is a temporary workaround for this ..
1) Edit /home/virtual/FILESYSTEMTEMPLATE/sendmail/etc/smrsh/responder.sh
(This file is hardlinked into all the domains having autoresponder enabled as /home/virtual/[domainname]/etc/smrsh/responder.sh)
and comment out:
${PYTHONBIN} ${RUNAPP} $@ > /dev/null 2>&1
so it looks like:
# ${PYTHONBIN} ${RUNAPP} $@ > /dev/null 2>&1
Then insert after it:
procmail -a "$*" /etc/auto.rc
2) Create the file called auto.rc with the following lines:
Copy this file to /home/virtual/[domainname]/etc/ for all the domains using autoresponder.
(You may want to use virtDomain.sh to automatically copy or create this file when ever a new domain is added)
Now anything coming from MAILER-DAEMON or postmaster that goes to the responder will be sent to /dev/null.
Anything else will be sent to the responder.