I really don’t know if it’s possible or not, and how difficult would it be to implement. For now we’ve got the following situations:
If we suspend an account for any reason we start to get messages from BFM about brute-forcing for that account (which is not a real brute-force attack, but an offline email program, which still tries to connect to the server and retrieve/send emails), and as soon as we unsuspend it back, we already have some IP(s) blacklisted. And even a customer can pay a prolongation and get his account running back again he/she gets nerves as of being not able to connect to our mail server as usual. So a customer should contact us to get the IP out from the black-list.
So, I’d like to ask you for an ability for us, which would allow to skip failed logins into MAIL/FTP server for suspended accounts.
Note, since the account is suspended none brute-force attack would ever succeed.