All of a sudden I cannont send mail through our main account, we receive
mail just fine. I have another account for work with outlook express where
I switch Identities and log into and that one is just fine, I can send mail
from my second account to my main but cannot send out of my main. I checked
all the mail account properties with the main account and all is fine, both
are through adelphia.net using Outlook Express 6.. Below is the message I
get when trying to send out mail in the main account:

"The message could not be sent because the server rejected the sender's
e-mail address. The sender's e-mail address was 'pmt122@adelphia'. Subject
'News Report.ppt', Account: 'mail.adelphia.net', Server:
'mail.adelphia.net', Protocol: SMTP, Server Response: '553
adelphia.adelphia.net does not exist', Port: 25, Secure(SSL): No, Server
Error: 553, Error Number: 0x800CCC78"