I was very proud of myself when I cooked up the following to backup and
encrypt my email to CSE's shiny new selfbackup server in a
streaming manner. Assuming you've set up GPG and your environment sets
$EMAIL and $USER appropriately, this will encrypt
a tar archive of ~/Library/Mail using your public
key:
tar c ~/Library/Mail/ |
gpg -e -r $EMAIL |
ssh selfstore.cse.unsw.edu.au "cat - > /backups/$USER/.mail.gpg &&
mv /backups/$USER/.mail.gpg /backups/$USER/mail.gpg"
Decryption is just a matter of gpg -d | tar x.