A migration is considered billable if 90% of the items migrated successfully. The formula is:
Items migrated/Items migrated+errors. If this number is greater than or equal to 0.9 the migration is considered successful and billable.
Each mailbox can be migrated successfully 10 times. If a mailbox is migrated successfully an 11th time, the mailbox will be billed again.
Note: If the error threshold was reached or the migration manually stopped then the migration is not considered billable.
The tool does not apply any charges to the credit card when it is provided, there is just a $0 authorization to validate the card. We bill monthly or quarterly based on usage only and payments are only processed once a day, at 10:00 PM PST.