POP3 relay issues

[PaulGillespie]

Most of my users on this exchange server use outlook in exchange mode but i need one remote user to use pop3. Her account is set up and she can download emails but she cannot send emails, it says:

550 5.7.1 unable to relay for paul@externaldomain.com

I can sent to internal email addresses fine but not external ones.

In outlook, the outgoing smtp server is the same as incoming (mail.company.com) and i'm using authentication (same as incoming server). I've set it this way up loads of times on other exchange servers and never had a problem.

The problem is with any email client on any PC. I think it's down to the exchange config.

The external user using pop 3 can send emails to people within the domain but if we try to send emails to another domain it fails with the errors above.

I have set up TLS on this server recently, would this affect it in any way? I've checked the SMTP virtual server config against a working one on anothe exchange 2003 server and they are the same. Am i missing something?

Thanks!

Paul

 

[PaulGillespie]

This is what i get in the smtp log:

2007-08-17 09:27:17 PaulPC SMTPSVC1 SBS2003 192.168.0.1 0 EHLO - +PaulPC 250 0 291 11 0 SMTP - - - -
2007-08-17 09:27:17 xx.xx.xx.xxx PaulPC SMTPSVC1 SBS2003 192.168.0.1 0 QUIT - PaulPC 240 875 330 9 141 SMTP - - - -

xx.xx.xx.xxx is my external IP!

Cheers

 

[itaviator]

Not real familiar with Exchange, but you said it's a "remote user". Do you need to allow smtp relay for that user's ip address?

Systems Administrator

 

[PaulGillespie]

The user is on a dynamic IP so can't allow that IP address. It normally authenticates on username, just not this time.