How do I set msExchMailboxGUID using powershell or any other method?
Solution 1:
Continuing from your example, this would work:
$guid = $user.get("msExchMailboxGUID")
$thisDN2 = $twoUser.DistinguishedName
$user2 = [ADSI]"LDAP://$thisDN2"
$user2.put('msExchMailboxGUID', @($guid))
$user2.setinfo()