Some time ago I wrote a post about MRSProxy.svc problems:
http://exchange.ittips.eu/2014/01/office365-new-mailboxmoverequest-causes.html
http://exchange.ittips.eu/2014/01/office365-new-mailboxmoverequest-causes.html
I have not got into account migration endpoint settings.
When this issue appeared again and I cannot move mailboxes to the Office365 at all, then I have checked endpoint settings.
It seemed that the password used for migration endpoint has been changed by other administrator and was not refreshed in Office 365 panel.
After entering password again, I can again move mailboxes!
To change migration endpoint password, go to:
Exchange administrative panel, users, migration.
On the right, low corner, check migration endpoint , click Details
Change password for administrator or enter new admin credentials.
When this issue appeared again and I cannot move mailboxes to the Office365 at all, then I have checked endpoint settings.
It seemed that the password used for migration endpoint has been changed by other administrator and was not refreshed in Office 365 panel.
After entering password again, I can again move mailboxes!
To change migration endpoint password, go to:
Exchange administrative panel, users, migration.
On the right, low corner, check migration endpoint , click Details
Change password for administrator or enter new admin credentials.