Hi

Environment:

2 Sites/subnets, STO and GBG, one domain
1 Trusted domain, SEGBG, has its own subnet behind a WatchGuard firewall.
2 CAS servers, one in each site STO and GBG
5 MBOX Servers with DAG in STO and GBG
Webmail/RPChttp-proxy uses split DNS int and ext, owa.servers.se

Users in the trusted domain is OK if connected to the CAS in GBG-site.
If they are connected to the CAS in the STO-site Outlook will not connect and webapp, OWA gives an error:
:-(
something went wrong An unexpected error occurred and your request couldn't be handled. X-OWA-Error: System.ArgumentException X-OWA-Version: 15.0.913.21 X-FEServer: CAS-SERVER (in STO) X-BEServer: MBOX-SERVER (in GBG) Date: 2015-03-05 13:11:08

Users in the server member domain that is on the same subnet as the trusted domain have no problems.
Problem is consistent internally and externally.
AllowCrossSiteRPCClientAccess is True

All servers involved, DC, DNS, Exchange can ping and connect via https/RPC/LDAP Http error codes in the Exchange IIS log that I have seen is 302 and 304.

No Denies are seen in the WatchGuard firewall log.

1 of 10 logins at the Web App works to make it more confusing.

Any ideas?

Regards Robert

Hi Robert,

Thank you for your post.

This is a quick note to let you know that we are performing research on this issue.

Best regards,

Hi

Opend a case with MSSupport also. REG:115030612481391
Very confusing for them also. Upgraded to CU7, made it a little better but the Linked mailboxes still have problems.

the search goes on!

Regards
Robert

Hi

I think CU7 fixed my probems. I now have other problems that I will post in a new thread.
Thkan you.

Regards
Robert

• Marked as answer by Robban Eriksson 21 hours 34 minutes ago