You can add & edit the phrases the Add2it Mailman Pro & Add2it MailResponder Pro Bounce Manager will look for in bounced emails inside the "Bounce Manager" section.

Unrecognized bounce messages can of course always be simply deleted. Or you add new phrases inside the "Bounce Manager" section to teach the system how to deal with those bounce messages.

You can also adjust the number of bounce points each particular kind of bounce message will give.

Also, you will find two values in the "Script Settings" section that allow you to modify the way the script deals with bounces...

If the threshold is like in the above screenshot, 10... and you want a particular hard bounce (e.g. mailbox doesn't exist) to cause an immediate delete of the subscriber... then the phrase "mailbox doesn't exist" could give 10 bounce points.

In other cases you might want to be more forgiving, for example for bounces of the type "mailbox full" you might only want to gibe 2 bounce points, so only if that bounce happens 5 times within 90 days the subscriber gets deleted.