XFOR: Err Msg: The Selected Postoffice is Read Only...

SUMMARY

When you migrate users from Microsoft Mail for PC Networks using the Microsoft Exchange Migration Wizard, you may receive the following error:

The selected Postoffice is read only. It must be writeable.

Verify that the Master.glb file is not locked open. For more information about this problem, please see the following article in the Microsoft Knowledge Base: If it is not locked open, running the MAILINT utility against the postoffice will return the following error: Checking the permissions of the GLB subdirectory will show that the subdirectory has Read Only permissions. Removing that restriction will allow the Migration to complete successfuly.

Note: MAILINT is a utility that checks the basic integrity of an Microsoft Mail postoffice. It is available in the Microsoft Mail Resource Kit.