Ever wonder how Exchange determines the FQDN for the \\.\BackOfficeStorage\<FQDN>\MBX or http://exchangeserver/exadmin/admin/<FQDN>/MBX?  This FQDN just so happens to come from the Default Recipient Policy object in the AD.  This object has the property “gatewayProxy” which contains both an X400 and SMTP address.  The SMTP address portion of this property is used as the FQDN in the above listed paths.

- Chris Ahlers

Not applicable
This is

"LDAP://CN=Default Policy,CN=Recipient Policies," + strOrgDN


Where did the name BackOfficeStorage come from?
Not applicable

Correct. You can tell if a policy is the default policy by looking at the msExchPolicyOrder attribute -- the value should always be 2147483647. There is a multivalued attribute called gatewayProxy on the object. The primary SMTP address begins "SMTP:" -- note that there could be secondary SMTP addresses beginning "smtp:" (lowercase) so check the case on the value. Also, only pull what is after the "@" since there may be specifiers such as %g or %s in the user portion.