NM: Migration Log, migrated messages + skipped messages not equal to total messages (4313574)

Issue

I was reviewing the migration log, and noticed the counts did not add up for skipped messages, and messages migrated to equal the total messages.  Why is this?

Solution

The final summary of skipped items is not meant to calculate to the total sum of messages.
In the Per Folder Count Summary, the “Other” field is a calculated value of the total items in the folder minus the migrated and skipped items. All documents in the folder may not be “valid” items to be migrated – calendar updates, or responses are examples of items that may be present in a folder but not be migrated nor skipped, so would be counted as “other”.
Since a message can appear in multiple folders, they are included in the total document count for the folder, so any item not migrated nor skipped for a documented reason is accounted for in the other (calculated) count. This shows that all items in the folder were evaluated. The total of all documents in all folders will not match the total documents in the database.