After moving mailboxes across forest using ADMT.
If users are using Password Export Server to Export their passwords
After moving the mailboxes across forest using ADMT.
Users will be prompted to change their passwords at their first logon
“You are required to change your password at first logon”
If you feel you got to disable that , You won’t able to disable it using GUI
Open Active Directory Users and computers – View – Advance Features
Go to User properties – Attribute Editor
Set “PwdLastSet” attribute to –1
Now User won’t be getting the below prompt
You can Search for Tools like Admodify to do it in bulk