When people are communicating on Mailman3 lists, some set up automatic responders for out-of-office, etc. and get let through the system to list recipients.
Unfortunately, this is bad behavior and appears to not be caught by default. I'd like to set up some kind of rule globally rather than per-list that would check if a message is an automatic reply (based on a set of criteria we've come up with programmatically on our previous custom implementation of lists) and then default-discard those messages.
Is there a way with custom rules to implement this? We're looking for certain strings on the subject line or other headers to determine "Discard" cases in our custom list implementations, but we are hoping we can implement this with customized rules in Mailman3 to achieve this goal. How would we structure that type of rule, and do we check the message object or the msgdata instead?
Thomas