exchange 2013 outlook server name is my owa URL not hash

i was migrating from exchange 2003 to 2010 to 2013.

after the migration and i install the exchange 2013 with exchange 2010 and configured it. the outlook not working with users that migrated to exchange 2013, and working well with the users already existing on exchange 2010.

when i try to fix this issue i set my outlook provider using this commend   Set-OutlookProvider EXPR -CertPrincipalName"msstd:mail.mydomain.com"

but unfortunately it's impacted the server name in client outlook.

then i removed the outlook provider and create it again. but with no change. then i uninstall the CAS server and install it again but with now change too.

now the outlook server name is my URL "mail.mydomain.com" and i need to recover it to be hash like "c4eb30b0-50ce-46fa-a019-c94851d99fda@mydomain.com"

the outlook client version outlook 2010 sp2 & and outlook 2013