Here we go again, when are you lot going to secure your email servers. It`s common knowledge that you are getting hacked on a weekly basis yet here I am getting more mail bounced back to me as undeliverable when I haven’t sent any in the first place. I use SSL through port 993 so I know its not me. If you dare to sent me an email to say its my fault I might just throw the towel in, OK.
Welcome to our forum, I am sorry you are having problems with non delivered emails. If you have not sent it then it is most likely that the spammers know of your email address and are spoofing. We have an article that explains more here Email Spoofing
I do not know of any one hacking our mail servers, sometimes customers mailboxes are hacked as passwords are guessed or leaked by malware on their devices but we always let them know about it.