cant send email error 550 - add to previous message today

[sregina1]

The message could not be sent. The authentication setting might not be
correct for your outgoing e-mail [SMTP] server. For help solving this
problem, go to Help, search for "Troubleshoot Windows Mail", and read the
"I'm having problems sending e-mail" section. If you need help determining
the proper server settings, please contact your e-mail service provider.

The rejected e-mail address was 'null'. Subject 'Re: Hi', Account:
'pop.comcast.net', Server: 'smtp.comcast.net', Protocol: SMTP, Server
Response: '550 5.5.0 <null> domain name required', Port: 587, Secure(SSL):
No, Server Error: 550, Error Number: 0x800CCC79

 

[PA Bear [MS MVP]]

Double-check the email address you're sending the message to. The error
suggests it's, e.g, 'JohnSmith' and not '(e-mail address removed)'

 

[Sam Hobbs]

I hope PA Bear's answer helped, but the part that says that the "e-mail
address was 'null'" looks suspicious to me. There might be something more
happening here, such as interference from an antivirus program.

 

[jensen1977]

Please tell me how you stopped this message from appearing each time you sent
other emails. I don't know how to get this done. Thanks.

 

[t-4-2]

1.) Always, Always, start a new thread for yourself.
Do not " piggy-back " other posts. You might have a similar problem, but the
cause of your problem may not be the same as the original poster.
2.) Post YOUR error message, verbatim.

t-4-2

Please tell me how you stopped this message from appearing each time you
sent
other emails. I don't know how to get this done. Thanks.

The message could not be sent. The authentication setting might not be
correct for your outgoing e-mail [SMTP] server. For help solving this
problem, go to Help, search for "Troubleshoot Windows Mail", and read the
"I'm having problems sending e-mail" section. If you need help
determining
the proper server settings, please contact your e-mail service provider.

The rejected e-mail address was 'null'. Subject 'Re: Hi', Account:
'pop.comcast.net', Server: 'smtp.comcast.net', Protocol: SMTP, Server
Response: '550 5.5.0 <null> domain name required', Port: 587,
Secure(SSL):
No, Server Error: 550, Error Number: 0x800CCC79