Question : 550 RELAY NOT PERMITTED when sending mail to external recipients via JAVAMAIL

I read here about the email problem some people are having with getting 550 RELAY NOT PERMITTED.

I am having the same problem when using JavaMail to send emails through my internet provider. From the info I read on the subject, I didn't see any programatic resolution or configuration I can use to resolve this issue.

The following are my test cases for this problem -

When executing the tests from JAVAMAIL:

From [email protected]
To [email protected]

SUCCESSFUL

From [email protected]
To [email protected]

550 RELAY NOT PERMITTED

When executing the same test from Outloook Express:

From [email protected]
To [email protected]

550 RELAY NOT PERMITTED

When executing the same test from patmedia.net's email website:

From [email protected]
To [email protected]

SUCCESSFUL

I still don't understand from the comments before me why this is occurring. Why can I email from patmedia's site, but not from outlook express or from Javamail to external email accounts? How do I resolve this - both through Javamail and Outlook Express?

Someone please throw me a bone here.... This is most annoying!

Thanks for your support,
- Mike

Answer : 550 RELAY NOT PERMITTED when sending mail to external recipients via JAVAMAIL

That is almost certainly the issue. Many ISP's will only relay mail if the source IP is one of their customers. You'll need to contact PATMEDIA and see if they offer SMTP AUTH, which would allow relay from an external IP.