I need to add functionality a bounce handler for multiple virtual domains that are constantly dynamic. I have over 1,000 domains that change (additions & deletions) on an hourly basis. Essentially, when an unsubscribe request, bounce, or a XDATA complaint comes in, it will go to one of several email addresses including bounce@whateverthedomainis.netThe functionality I need to add is to set up sendmail to relay all bounce@* and abuse*@* to an IP that acts as a smarthost. All other emails must be processed locally as there are automated mailboxes on the machine that process formatted emails.I originally had it set up to where my bounce server was an open relay to the smarthost IP and I was assured that they would handle security, however they didn't and we quickly became a relay for spammers.
Using wildcard domains in sendmail
sendmail