I have a basic standalone script,
UBB.threads Bounced Email Processor that I wrote in 2016; I use it to login to my forums IMAP account and process any bounces (either disable UBB.threads emails, or generate a list of bounce-backs), can delete the bounce back messages on the server, can add users to a defined group on UBB.threads, and support sending login information over SSL on a POP3/IMAP server. I only run it as a cron task however, so it automatically processes bounces; but it does have a web interface, however you're at the mercy of the PHP setting "max execution time".
It'd take some playing with the system to get it to run smoothly, especially if its your first time running it and you have a significant amount of messages to go through.