I just upgraded my environment from Exchange 2007  SP3 to Exchange 2013 CU7 i coexist mode.   We have 2 CAS servers (2007 and 2013) and 2 Mailbox server (2007 and 2013).  Everything work - OWA, autodiscover. But the only way I can get the client Outlook to work is if I manually add "DS Server" in the registry  and point to the DC. I cannot undestand why client computer can't see the GC? Some strange thing also - there is not problem for Outlook clients to connect in virtual workstations or Citrix clients (the same user) !  

Can somebody help me?!!!

• Edited by ElenaNorge 4 hours 40 minutes ago

Hi ElenaNorge,

According to your description, I understand Outlook client cannot connect to Exchange server until add "DS Server" in the registry that point to the DC after upgrade from Exchange 2007 to Exchange 2013.
If I misunderstand your concern, please do not hesitate to let me know.

I want to double confirm some points, please help to collect answers for following questions:
1. Internal or external outlook client experience this issue?
2. Did you change the DNS record and certificate for new Exchange server?

Please pay attention to below blog for Step-by-Step Exchange 2007 to 2013 Migration and How does Outlook Anywhere work:
http://blogs.technet.com/b/meamcs/archive/2013/07/25/part-2-step-by-step-exchange-2007-to-2013-migration.aspx
http://blogs.technet.com/b/exchange/archive/2008/06/20/3405633.aspx

If the issue persists, please post the related error message, its more helpful for further troubleshooting.

Best Regards,
Allen Wang

Hi Allan,

og thanks for your response.

 "I understand Outlook client cannot connect to Exchange server until add "DS Server" in the registry that point to the DC after upgrade from Exchange 2007 to Exchange 2013." - it's right. But Outlook clients in virtual workstations and Citrix clients has no problem.

1. Internal or external outlook client experience this issue?  - internal. External used OWA - no problems
2. Did you change the DNS record and certificate for new Exchange server? - Yes. I have "legacy.." DNS record for 2007 and "webmail.." for 2013. Certificate is installed  for the new server. We use wildcard sertificate.

We got just standard error "Outlook unable connect......"

Is it some ideas what I must check?

• Edited by ElenaNorge 1 hour 9 minutes ago