Some of my Email contacts get a mailbox full message when responding to my Email.
i have been trying to resolve this problem for over a year with Xfinity with no success??
And your mailbox isn't full? You get 10GB storage among all folders and your Inbox. How much have you used?
@Kenton please PM me with the email you are having this issue with a copy of the bounceback message if possible so i can review further