It looks like AT&T is rejecting all the eMails from the cluster that contains our server. A friend of mine is going to get this problem fixed, but I do not know how much time this will take.
In answer to AT&T customer Ed Kimball‘s question:
In order to open (or to create) a password protected archive, you have open the 7-Zip archive you want to decompress/drop the files you want to compress over 7zX’s icon, and then keep pressed the “P” key until the password dialog comes up.
Hope this helps,