You're welcome. Comcast has a habit of changing things fairly often, but I
don't know if this is recent or not. If you do find that some settings
become unchecked seemingly on their own, keep this in mind.

Settings that become unchecked may be caused by one or more of the following
programs. There are probably others that will do it as well.

Ad-aware's Ad-Watch
IBM Access Connections
McAfee VirusScan and/or Antispyware
Norton AV
Spyware Blaster
Spybot Tools IE Tweaks
Spybot- Teatimer
Spysweeper
Spyware Doctor
Windows Defender
Zone Alarm (free) 6.5 Reported to be fixed in later versions.

In the case of Zone Alarm 6.5 or Norton 2007 it actually has to be
uninstalled. Make sure the Windows Firewall is turned on until you
reinstall Zone Alarm.

Boot into Safe Mode with Networking and try the change.
--
Bruce Hagen
MS-MVP Outlook Express
Imperial Beach, CA


"Bob W" wrote in message
...
Thank you, thank you Bruce and Ricky!! Checking the "Authentication" box
fixed it. I wonder why it wasn't working before since I have done nothing
with my accounts? I don't know whether the box was checked or not before
the
problem. Can in arbitrarily uncheck or work without it being checked?
Again, your help was appriciated! Have a great day. Bob

"Ricky" wrote:

On the tools..accounts..mail..properties..server tab make sure the 'My
Server Requires Authentication' box is checked.

"Bob W" wrote in message
...
Thanks for response, Bruce.
I have already phoned Comcast and these were correct: POP3;
mail.comcast.net; smtp.comcast.net. Is that what is meant by
"authentication
checked"?
Bob

"Bruce Hagen" wrote:

Tools | Accounts | Mail | Properties | Servers. Is: My Server Requires
Authentication checked? The error message suggests that it should be.
--
Bruce Hagen
MS-MVP Outlook Express
Imperial Beach, CA


"Bob W" Bob wrote in message
...
Outlook Express has been used for a long time with no problems and
nor
alterations have been made. 4 days ago the sent emails were
rejected.
I
turned off computer over night and it worked again the next day.
Then,
yesterday, the sent emails were rejected and I shut off computer
overnight.
Error problem still exists. Receiving emails works OK. I can send
OK
through webmail at Comcast, but not from OE. Here is the Microsoft
error
message:

The message could not be sent because the server rejected the
sender's
e-mail address. The sender's e-mail address was
'.
Subject 'testing', Account: 'Bob Wilmot', Server:
'smtp.comcast.net',
Protocol: SMTP, Server Response: '550 5.1.0 Authentication
required',
Port:
25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC78