I’ve decided that I want to try to reduce my dependence on Google’s services. A large part of my Google footprint is Gmail, which I have used for about 15 years.
I’ve not entirely planned through my migration yet, but I think I want to use email in a more transactional manner, as was intended; I want to retrive emails from a server, store and back them up locally on hardware which I control, and then send via SMTP. I really don’t find having access to my email via a browser that convenient as it’s rare I don’t have a laptop or a phone from which I can SSH into my own computers. Push notifications for email are an annoyance; I’d rather interact with my email on my own schedule in batches.
No matter what the overall plan, the first step is to being to sync a considerable volume of email from Google’s servers to my own computer.
For this, I’m using isync, which can reliably sync email from GMail’s IMAP servers to a local Maildir, in one (or both) directions. Note that while the package is called
isync, the binary I’m using is called
mbsync, and the configuration file is
isync can sync mail in both directions is important as I want to initially have my local setup mirror my current GMail setup, with access via either method, and to later transition to only downloading from GMail.
It’s also necessary to setup an ‘App Password’ in GMail, which will allow IMAP access to your mailbox outside of the usual Google Account authentication flow. Once that password has been created, I suggest you encrypt it locally and extract it via gpg (as the configuration below demonstrates).
My configuration file (
~/.mbsyncrc) is as follows:
IMAPAccount personal Host imap.gmail.com User email@example.com PassCmd "<run gpg here>" SSLType IMAPS CertificateFile /etc/ssl/certs/ca-certificates.crt IMAPStore personal-remote Account personal MaildirStore personal-local Subfolders Verbatim Path ~/mail/personal/ Inbox ~/mail/personal/inbox Channel personal-default Master :personal-remote: Slave :personal-local: Patterns * ![Gmail]* Create Both SyncState * Sync All Channel personal-sent Master :personal-remote:"[Gmail]/Sent Mail" Slave :personal-local:sent Create Slave Sync Pull Channel personal-trash Master :personal-remote:"[Gmail]/Trash" Slave :personal-local:trash Create Slave Sync Pull # Get all the channels together into a group. Group personal Channel personal-default Channel personal-sent Channel personal-trash
isync configuration files are in an odd, stanza-based format. The concepts are based around groups and channels. A channel is a bidirectional mapping between a two mail stores (in this case the remote IMAP server and the local Maildir, but this could just as easily be two remote IMAP services). From top to bottom, that configuration file does the following:
- Define the
IMAPAccount, and it’s credentials.
- Setup SSL
- Setup the
IMAPStoreon the account.
- Setup the local mailbox.
- Define a channel to map the remote mail to the local mailbox.
- Define a channel for the ‘Sent’ folder.
- Define a channel for the ‘Trash’ folder.
- Finally, setup a group called ‘personal’ which is made up of those channels.
The first sync will take a long time (for my decade and a half of email, to my home server over a 75mb link it was around a day, but that also accounts for some gentle throttling on the remote IMAP service). I ran this in a
$ mbsync -Dmn personal
Once the initial sync has completed, subsequent activity will be much quicker. I use the following
systemd timer and service to sync every five minutes:
$ cat /etc/systemd/user/mbsync.timer [Unit] Description=Mailbox synchronization timer [Timer] OnBootSec=2m OnUnitActiveSec=5m Unit=mbsync.service [Install] WantedBy=timers.target $ cat ~/.config/systemd/user/mbsync.service [Unit] Description=Mailbox synchronization service [Service] Type=oneshot ExecStart=/usr/bin/mbsync -Va