This relates directly to this post:
Had the same problem as in the post listed above. PCI compliance scan returned the error quoted in the title. I used the accepted solution given by JerrytheGreat, and it worked - I reran the PCI compliance scan, and passed. However, now I'm unable to access Outlook Web Access from within my network, using either the mail.mydomain.com/exchange
URL, or the internal IP/exchange address. Outside the network, OWA is working fine. I did restart IIS after applying the solution, like the post indicated.
The post I linked to mentions problems with OWA, but says that the script in the Accepted Solution doesn't cause any problems with OWA. In my case, it appears to have caused a problem.
Any help is appreciated.