Email down

Since yesterday (12Nov) at 10:30, my email has not been working via MS Outlook, my Treo phone, or mail.xxxxxx.xom. Squirrel mail works as does my FTP site and website. Both MS Outlook and my Treo phone constantly request confirmation of my password. I comply and the same dialogue box appears without success in send/receive.

I posted a support request immediately and another 7 hours later. No reply. Any ideas of what can be the issue?