Need confirmation on the behaviour for scenario below.
Migration starts for user A, option selected is to migrate ALL Email (no date range filters applied).
Migration completes successfully. However there are unforeseen issues so MX switch-over did not go ahead for x weeks.
As x weeks have passed, User A needs to be migrated again, however what option should be chosen:
a) Migrate with ALL Emails
b) Migrate using Date Range - set start date to 1 day prior to previous successful migration and end to date in future
Will choosing option b) be quicker than option a) or does it not make any difference?
Will choosing option b) still cycle through all previous emails and migrated and skip as they were already migrated or will the tool only start looking at email from the date ranges specified ?