I have an issue with Outlook Clients when adding a new mailbox that is hosted on Exchange 2013 in a coexistence with Exchange 2007 (on premises). The co-existence is temporary until all mailboxes are migrated to Exch2013 and then will decommission exchange 2007. The current environment is as follows.
- 1x CAS (Windows server 2003 Ent 64Bit)
- 2x Mailbox Severs (DAG enabled) (Windows 2008 Ent)
- 2x CAS (Win2008 R2 Standard)
- 3x Mailbox Servers (DAG Enabled) (Win2008 R2 Datacenter)
- Barracuda Load Balancer setup for mail flow and CAS HA.
- 1 Forest and 1 Domain
Overview of the current Exchange Status.
- Emails are accessible internally and externally via OWA and Outlook client on both exch2007/2013 servers.
- Adding a new mailbox in outlook onto Exchange 2007 resolves to the correct CAS (Ex2007) successfully.
- Adding a new mailbox in outlook onto Exchange 2013 gives the error (refer to attachment)
Adding outlook client was working perfectly during the initial configuration and testing. However, after installing Exchange 2013 CU10 on all the Exch2013 servers, I started to encounter the error.
It could be a CU10 bug but tried every information I can find on the web but none works.
Would appreciate a resolution please.