Got Your Back - Got Your Back (GYB) is a command line tool that backs up and restores your Gmail account.
imapsync - Console-based utility for migrating IMAP mailboxes.
Gmvault - Backup the emails in your Gmail account.
SysTools Gmail Backup - Backup Gmail Emails, Contacts, Calendar, and Google Drive Storage File by SysTools Gmail Backup Solution
Cryoserver - Cryoserver is an all-in-one email archiving solution that empowers you to preserve your email in a tamper-evident archive, making you transform your data into a useful archive for everyday use.
Softaken Gmail Backup Pro - Backup Gmail emails to local PC with Softaken Gmail Backup Tool