Cannot get to 1 external web site

I just removed ISA 2004 from an SBS 2003 server.  I did all per the steps given by Microsoft and everything seems to be working PERFECTLY fine except 1 site.  From INDSIDE the domain, we cannot get to the OWA site that has a completely different name than the local domain (dimain is ABC.local and the email and OWA is  We can get to but as soon as we try to go to /exchange it fails.  All access to it is perfectly fine from outside of the office but inside users access the web site and a link to there OWA email from there.
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

David Paris VicenteSystems and Comunications  Administrator Commented:
Can you specify please.

Remove Isa but you install other Isa server?
cirving13Author Commented:
No, I installed a SonicWall TZ215 device.
David Paris VicenteSystems and Comunications  Administrator Commented:
Ok. Probably you have to check the certificates on the firewall.

DO you install the OWA/Exchange certificate on the firewall?

Let us know.
Newly released Acronis True Image 2019

In announcing the release of the 15th Anniversary Edition of Acronis True Image 2019, the company revealed that its artificial intelligence-based anti-ransomware technology – stopped more than 200,000 ransomware attacks on 150,000 customers last year.

cirving13Author Commented:
No but again, it works perfectly fine from outside of the office so I assume it is not a cert issue.
David Paris VicenteSystems and Comunications  Administrator Commented:
Oh ok misunderstood sorry.

IIS logs on the exchange server what are they reporting. Any error´s or warnings?

Can you put them in here
If your web site served from a host on the lan, or hosted outside?

Your problem is that the Sonicwall will not permit traffic from the LAN to address content on the WAN ip address. You need to use the internal lan name or ip for the OWA server. Or, if you have your own dns server, then chang resolution for to reference the lan ip.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today

From novice to tech pro — start learning today.