NM: Receiving "database would exceed its disk quota." error messages in migration log (4310025)

Issue

I've found these errors in the migration log. What is causing them?

Error: Failed to open document: Unable to write to database because database would exceed its disk quota.

Solution

This error may be caused by a Domino/Notes mail file quota.  During a migration, CMTe is opening the user's mail database and will read every view and or folder. By doing this, CMTe has to index the view that was not already indexed by the user

The index is part of the nsf file structure, so it is included in the overall database size.  If quotas are enabled, it will prevent any further action when the file size is exceeded. CMTe cannot open the views and or folders because the mail file has reached the quota.

To proceed, you must remove the quota.  You may enable the quota once the migration has completed successfully