MS Outlook-The server responded: 554 Sending address not accepted due to spam filter

[wildrumpus]

I created a new account in my MS Outlook (2007) according to the email I received from hostek. In Outlook, I clicked the Test Account Settings button. It shows a successful log onto the incoming mail server (POP3), but Send test e-mail message fails with this error: 554 Sending address not accepted due to spam filter. Do you know how I can fix this?

[chrisd]

wildrumpus

Please provide the domain this is regarding to "http://support.hostek.com" so we can check the mail server IP that your domain is sending mail through to verify if this is on any blacklists.

[wildrumpus]

The fix was: Make sure that you have "my server requires authentication" selected in your More Settings.
That was indicated in the "Cannot send/receive from my email client" sticky, but had mentioned a different error than the one I saw.