I have an Exchange 2003 server with POP3 running. Our internal domain is internal.com. Our external domain is external.com. The win2k domain the users logon to is domain1. The mail server is mail.internal.com. I have a DNS entry inside so that if any internal user accesses mail.external.com it works.
If I’m on an internal PC logged into domain1, and I configure Outlook express to use mail.external.com as the incoming and outgoing server, I can send and receive mail.
If I go to a PC outside the network, I cannot authenticate to the server. I’m allowing POP3 and port 995 traffic through the firewall, and when Outlook Express tries to connect I see “connected” in the details window. The failure seems to be in the authentication.
In the Outlook client, I’ve tried DOMAIN1\USERNAME in the logon settings, I’ve tried USERNAME, I’ve tried USERNAME@external.com. None seem to work. I am not requiring SSL.
I also tried NOT logging into my domain on a PC inside the network, and just logging on to a local account on the PC. It still works fine.
So what am I missing? Based on these symptoms I would think it’s a firewall issue, but I don’t see what else I could allow through the firewall.
P.S. The only other thing is that incoming SMTP mail gets routed through an antispam server before going to the Exchange server. But, I don’t think this is an issue because outgoing mail from the client does not require authentication.
I hope all this information is useful, not confusing….
If I’m on an internal PC logged into domain1, and I configure Outlook express to use mail.external.com as the incoming and outgoing server, I can send and receive mail.
If I go to a PC outside the network, I cannot authenticate to the server. I’m allowing POP3 and port 995 traffic through the firewall, and when Outlook Express tries to connect I see “connected” in the details window. The failure seems to be in the authentication.
In the Outlook client, I’ve tried DOMAIN1\USERNAME in the logon settings, I’ve tried USERNAME, I’ve tried USERNAME@external.com. None seem to work. I am not requiring SSL.
I also tried NOT logging into my domain on a PC inside the network, and just logging on to a local account on the PC. It still works fine.
So what am I missing? Based on these symptoms I would think it’s a firewall issue, but I don’t see what else I could allow through the firewall.
P.S. The only other thing is that incoming SMTP mail gets routed through an antispam server before going to the Exchange server. But, I don’t think this is an issue because outgoing mail from the client does not require authentication.
I hope all this information is useful, not confusing….
