Mail suddenly stopped working for 3 of our 5 email addresses on my MacBook Pro, iphone and ipad. I can check them on att.net, but it keeps asking for the password when trying on our Apple products. Is this a Mac/Apple problem or an Att problem? One of the emails worked today to receive the emails missed in the last week, but now doesn't recognize the password anymore. This happens periodically without us changing anything. The last time I called Att, they said it was not their problem. My children's email addresses seem to have this problem the most, but now my husband's email hasn't worked in a week. One issue Att said was that we needed to have an IMAP email instead of a POP account. I set up all new emails as IMAP and now they are not working either.