Can't send select emails

[Mothergoose]

I used to be able to send all emails, but a few months back, certain emails
would bounce. On the sample below, I asked a question on a website where I
had just placed an order. When it bounced, I sent the message from my
personal email account instead and it went through just find. It says it
isn't on my allowed list. How to I correct this?

Here is the error message I receive:

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 '(e-mail address removed)'. Subject 'shopping
Cart Error', Account: 'pop.secureserver.net (1)', Server:
'smtpout.secureserver.net', Protocol: SMTP, Server Response: '553 Sorry, that
domain isn't in my list of allowed rcpthosts.', Port: 25, Secure(SSL): No,
Server Error: 553, Error Number: 0x800CCC79

 

[Gary VanderMolen]

Make sure you have send authentication enabled.
Go to Tools, Accounts, select that account, Properties, Servers.
Enable the "My server requires authentication" option.

If the problem continues, change port 25 to port 80.