Today on creating user mailbox found the legacyExchangeDN is added with numbers in front of the alias name. This behaviour is not there in Exchange Server 2007 or 2010.
legacyExchangeDN: /o=First Organization/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=63e8dcabcae84802b1f03db4d02aa27c-Raji;
This will result on contact sync while using FIM products when it creats proxy address for the X.500 stamping. All the it’s know behaviour of Exchange Server 2013. I tried to disable them using the below powershell command..but it didn’t work.. 😦
Set-OrganizationConfig -IsGuidPrefixedLegacyDnDisabled $true
On digging much found in the technet article stating “This parameter is reserved for internal Microsoft use” from the technet article – http://technet.microsoft.com/en-us/library/aa997443%28v=exchg.150%29.aspx