SMTP Authentication

I tried lots of versions of thisand that to get an Smtp Authentication on Outlook. But I m still getting the error of;

Undelivered Mail Returned to Sender

Diagnostic-Code: smtp; 551 This mail server requires authentication before

sending mail from a locally hosted domain. Please reconfigure your mail

client to authenticate before sending mail.

Means; It isnt recognize my authentication method via Outlook. Also AppleMail and Thunderbird.

Also tried different authentication types in AppleMail, only "Password" options works. The other options even cant connect. My hosting service doesnt support SSL.

We can send emails via gmail or windows based email programs to the customers which need smtp authentication. But in Mac-Based ones, we cant.

Any ideas?