It’s pretty straightforward to (incrementally) backup all emails in a Gmail account to a QNAP NAS. There’s a QNAP NAS solution using Getmail but it comes with some limitations. I prefer to use Gmail-Backup. It doesn’t need any configuration files and it doesn’t have a 100 messages per session limit. It stores all mails in the .eml format, which not only works on Windows PCs but is compatible with Apple Mail as well. You can even restore deleted emails using Gmail-Backup from the NAS back to a Gmail account.
Here’s how I installed Gmail-Backup on my QNAP TS-439 PRO II+. This tutorial should work with all Intel-based QNAP TS-* models but obviously I only have the 439 to test with. I’m looking forward for your feedback if it works on your QNAP NAS model as well. Please make sure you enabled IMAP in your Gmail account settings. Gmail-Backup works for “Gmail for your domain” (it’s part of “Google Apps” now) accounts as well.
The tutorial is divided into three parts. The first part shows how to install the Optware QPKG on the NAS. This package installer is needed in order to (easily) install Python on the NAS. The 2nd part deals with the installation of Gmail-Backup and the third shows how to automate the backup using cron. It probably is helpful to have some command line skills. Read more »