Blacklisted by mistake??

Somehow I’ve managed to blacklist an email address I didn’t want to (they keep being told that I’m rejecting their mail), but there isn’t any email to move to folder and undo the blacklisting as I’m not receiving them at all. What do I need to do?

Hi, if you have blacklisted any email then go to Tools - Rules, find “Blacklist” rule, click on it and then click on modify.

Then from it delete email domain you want.