HT1277: Configuring Mail for your email accountLearn about Configuring Mail for your email account
Currently Being ModeratedJul 17, 2012 8:58 AM (in response to carmsquest)
Your SMTP server host name setting, your SMTP server port setting, whether SSL/TLS is needed or not, amd/or your server login username or password credentais, some combination of these, are likely incorrect here.
These are the typical triggers, when a send (or a forward) fails.
If you have more than one mail account configured within Mail.app, ensure that the mail account you are testing with is configured with the expected SMTP server, and is not referencing the SMTP server for another account.
Connection Doctor (available in the Mail.app menu bar Window menu) can sometimes help figure out some of these connection problems, too.