SBS 2003/IMAP question

[Jeremiah8]

All,
I have a rather random issue that I just can't figure out.

My setup is a SBS 2003 R2 server that I've enabled IMAP on. I have one user that is using IMAP to view his email. He's using it both in the office as well as at home. When I setup his email client to connect to our email server, mail.domain.com, and he's at home, he's able to get his email without issue. When he's in the office he gets an authentication error message. I then switch his server address to the internal IP of the server, it works without issue.

Does anyone have any thoughts on this? Other than just telling him to use Outlook w/ Outlook Anywhere.

J.

 

[58sniper]

Sounds like a DNS or routing problem. What's likely happening is he's attempting to connect to the mail.domain.com server, and the firewall doesn't like him going out and back in.

The likely solution is to create a forward lookup zone on your SBS box for your public domain name (domain.com). Then, create an "A" record for "www" and point it to your external website (so your internal users can get to the external website), and an "A" record for "mail" and point it to your internal SBS box.

That should fix it.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP
Want to know how email works? Read for yourself -

http://www.ietf.org/rfc/rfc2821.txt

 

[Zelandakh]

Outlook with RPC set up would be infinitely more preferable especially as you can then close the IMAP port.

But I agree with Pat, set up DNS internally so that the same FQDN he uses externally points internally to the mail server.

 

[Jeremiah8]

Pat,
Sorry for the delay in getting back to you. We have too many projects going at once.

Thanks for the advice, however when I created the forward lookup zone it didn't change anything.

Is there a good site to read up on the forward lookup zones? I don't actually have any formal training on this, MSCE, etc, this is just my boss saying this needs doing.

J.

 

[58sniper]

Once you create the forward lookup zone, you need to create the host record ('A' record) in that zone. Using your original post, you created a forward lookup zone for domain.com. You now have to create a host record for mail, and point it to the INTERNAL IP address of your mail server.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP
Want to know how email works? Read for yourself -

http://www.ietf.org/rfc/rfc2821.txt

 

[Jeremiah8]

Pat,
That did the trick. I was having one of those moments when I was following your original post and put the public IP of the mail server in there.

J.

 

[58sniper]

Glad to see it's working.

Pat Richard, MCSE MCSA:Messaging CNA
Microsoft Exchange MVP
Want to know how email works? Read for yourself -

http://www.ietf.org/rfc/rfc2821.txt