NM: Why are some messages missing from my Outlook folders after migration? (4320982)

Issue

For a specific mailbox, I can see +/- 1200 mails in source personal folder, while only a small portion of the messages migrated in Outlook. There are no errors in the migration log.

Solution

In the migration log, perform a search of the Personal Folder Name. You will see all the details of why these messages were not migrated.
Exporting folder '<FOLDERNAME>', xxxx documents...

You may see messages like the following:

Skipping: Encountered Document not selected for migration. Folder:

This means these documents do not meet the filter criteria you have defined for this migration. The formula is at the top of the migration log.

Skipping: Duplicate. Folder: <FOLDER NAME> NoteID:
FOLDERNAME -- Documents: 1200 Processed: 200 Skipped: 1000 Failed: 0

This means the message was encountered earlier in the migration, and has already been migrated. A single message may exist in multiple folders in Notes, but it can only exist in one folder in Outlook.

Troubleshooting Tip

When attempting to troubleshoot an issue of "my messages didn't migrate", get the subject line of a sample message, and search the migration log for any errors Ctrl+F error: or the subject line
Make sure you look at the migration log for the specific issue.

If the migration was completed without error (Migrated Successfully means the migration was able to start and complete without a crash, it does not mean 100% of the data moved from source to target), then contact the end user, and get a sample of what is missing.

It's possible the user is placing his Sent items into folders, or is storing received mail in multiple folders. Lotus Notes allows a single message to be stored in multiple folders, but Outlook does not, so we migrate the message to the first folder it's encountered, and skipped in all other folders.

Take the subject of the 'missing" message and perform an Advanced Find (Ctrl + Shift + F) in their Outlook mailbox. It's possible the message is in the Sent Items folder or another personal folder or the Inbox.

Note regarding Private Folders
If the folders are 'Private' then Domino security prevents the migration id from seeing these folders, and all items are placed in the Unfiled folder, but since you stated there are empty folders in Outlook, this means the id had access to the folders, migrated them, but the contact was migrated to another folder.