How to back up your Gmail/G Suite emails on a Synology NAS

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This weekend I reviewed my email backup strategy and decided to make daily backups of all my accounts directly on my NAS. Since they are all Google-based, I went with gmvault on my Synology server. Here’s a walkthrough.

There are posts online that achieve this using ipkg and compiling dependencies. As of this writing (DSM v6), this is no longer needed.

Note: I’m using the root account because I am the only user of that server. Also, this lets me set up a crontab without reloading the cron service between shutdowns and reboots, due to Synology’s peculiar cron management system. Keep this in mind if you are on a shared NAS.

Make sure you checked the Gmail setup beforehand.

Initial Setup

Log onto DSM, and install Python via the Package Manager.
Enable SSH in the Control Panel, under “Terminal & SNMP”.
Open a terminal and log in via SSH. You will be prompted for your password.
```
 ssh [email protected]
```
Switch to root. Use your password again:
```
 sudo -i
```

Download and install the Python Package Index:

 wget https://bootstrap.pypa.io/get-pip.py && python get-pip.py

Remove the pip setup script, and install gmvault:
```
 rm get-pip.py && pip install gmvault
```
Create a folder to store the backups, otherwise they’ll go to $HOME/gmvault-db:
```
 mkdir /volume1/gmvault
```
Run gmvault. Notice the --emails-only option since I don’t care about chats, and -d flag with my custom backup path:
```
gmvault sync [email protected] --emails-only -d /volume1/gmvault/your_account\@gmail.com/
```

It will run for a while now. Repeat steps 7 and 8 if you have multiple accounts.

Automated backups with cron

Now, let’s set up a cron job to have daily backups.

Open the crontab:
```
 vi /etc/crontab
```
Edit the crontab. For daily/weekly backups you can use -t quick. Note that entries must be delimited by tabs. This will run daily at 2AM :
```
0 2 * * * root  gmvault sync [email protected] --resume -t quick --emails-only -d /volume1/gmvault/your_account\@gmail.com/
```
Save your crontab and restart the cron service:
```
synoservice -restart crond
```

You’re all set!

Update (May, 25th 2018): A previous version of this article included a crontab that ran every minute for an hour, instead of once at a given hour. Thanks Kristian for the tip!