Understanding differential restores

SYSTEM INFORMATION
OS type and version Rocky 9.3
Webmin version 2.111
Virtualmin version 7.10.0
Related packages Backup / Restore

Good evening.

I have the following config:

1 Full backup every Sunday
Mon to Saturday is differentials, Each backup is to a different folder for each day.

According to the documentation when doing a restore I need to do the full then the latest differential.

My question is if a email is received on Tuesday, and the clients moves it to a different folder on Tuesday and it just sits there. Then I have to do a restore with the Thursday differential, will that email be restored?

Effectively the reason I am asking this is the email file has not changed since Tuesday, will it be part of the Thursday backup?

Or does Virtualmin go and look in each differential backup created and restore from Mon to Thursday, when restoring Thursday?

Will the email be restored with the Thursday restore?

Virtualmin will only use the one diff file, the email needs to be in that backup.

Your last diff should be the largest in size as it backing up what different on the server from when the full backup was made.