we enabled incoming e-Mails recently, after Microsoft implemented plus addressing in September. At the beginning it was working properly. Unfortunately, since a few days, it does not work anymore and e-Mails sent to our mailbox are rejected.
The error message indicates, that the mailbox does not exist. It seems this is due to the fact, that Moodle creates multiple "+"-signs in the reply email. It does not work with "username+AAAAAAAAAgAAAAAAAWuJtORL49+lzSJ+5Vj@ourdomain.at", but I can successfully send to "username+AAAAAAAAAgAAAAAAAWuJtORL49@outdomain.at", although obviously Moodle can not work with that message anymore.
Does anybody else also suffered from such a problem with O365 or has a solution?