I'm a sloppy person, so I set up a solution derived from a script I
snagged through googling.
The "sloppyness" principle suggests that I won't know exactly which
files to back up,
nor will I remember to make the backups.
Download the script and edit "dst=/mnt/backups/example.com.d", 'srcroot="email@example.com"', the "src='" section, and possibly the "filter='" section and "monthly=60".
Add appropriate entries to your crontab with the command
Remote backups will normally need to authenticate the SSH connection.
Rather than put a password in the script,
it is better to set up key-based authentication.
If there are large frequently-changing files,
the backups will use more space.
It might be reasonable to exclude some of those files from the backups.
This might work best if the files are automatically rotated with
During the initial weeks, you will get warning emails that some of the "--link-dest=" destinations do not exist. I just wait until they stop, but you could remove the offending "--link-dest=" lines and try to remeber to replace them later. They are only needed when something goes wrong with an hourly backup, so there will be alternative places to look.