If you want to export your mailbox from Google account then we recommend you to choose Jagware Gmail Backup Tool as its one of the best utility to directly export your Google data. It also offers Oauth authentication that makes this process to easier and also offers valuable results. It also offers advanced filter such as incremental backup, exclude attachments, export only sent folders and so more. This software offers simple intiative interface to easily perform by any professionals or individual users.
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