I believe the real issue here is its not uncommon for spam services to try to locate valid email addresses.  Generally, an email server won&#x27;t accept email to an invalid users and will probably start flagging the incoming server&#x2F;domain as those attempts start to cross a threshold of some sort.  OP is talking about *@example.com as a catchall which means a spammers script will sit there and email a dictionary of usernames against your domain until it crosses it&#x27;s own threshold.  It&#x27;s not too hard to add an alias for each name as you go along but it really depends whose list your domain gets on.