Migrating from offlineimap to isync

Recently I have been experimenting with the terminal email client mutt (neomutt to be specific) in preparation for setting up my own email server (I want to stop being over reliant on GMail).
Initially I stumbled upon offlineimap as a way of downloading and syncing mail from an IMAP server, but as it turns out it is built in Python 2 and considered a bit obsolete and slow by many. So after some searching I discovered isync as a suitable replacement and decided to migrate to it from offlineimap, a process I will document below.

To start with you need to be aware that isync is the name of the application but the binary provided is called mbsync.

My offlineimap config looked something like:

[general]
pythonfile = ~/.offlineimap.py
accounts = mail
starttls = yes
ssl = yes

[Account mail]
localrepository = mail-local
remoterepository = mail-remote

[Repository mail-remote]
type = IMAP
remotehost = mail.server.com
remoteuser = [email protected]
remotepasseval = get_pass("personal/email/lyndon")
sslcacertfile = /etc/ssl/certs/ca-certificates.crt

[Repository mail-local]
type = Maildir
localfolders = ~/.Mail/mail

In offlineimap you have the concept of an Account which is made from 2 Repositories. In my example one is a local Maildir repository and the other is a remote IMAP repository.

The configuration itself is incredibly simple, and even allows you to evaluate some code to get your password credentials (I use an application called pass).

isync’s configuration is a little different. But the concepts are similar:
Instead of a Repository the equivalent is called a Store in isync and what was known as an Account in offlineimap is called a Channel.
When dealing with IMAP isync allows you to separate the credentials out into an IMAP Account and refer to them in an IMAP Store, letting you use the same credentials for multiple Stores.
The format is not INI like isync but instead a more common rc style configuration file:

# Isync Mail Config

IMAPAccount mail
Host mail.server.com
User [email protected]
PassCmd +"pass personal/email/lyndon | head -1"
Port 993
SSLType IMAPS
SystemCertificates yes

IMAPStore mail-remote
Account mail

MailDirStore mail-local
Path /tmp/maildir/
Inbox /tmp/maildir/INBOX

Channel mail
Far :mail-remote:
Near :mail-local:
Patterns * # This syncs all Mailboxes
Create Near # This creates folders for all remote mailboxes
SyncState *

Thankfully this is not that complicated to adapt the previous config too.

Unfortunately I read that many had issues using the same Maildir they used in offlineimap with isync so to avoid this issue I decided to delete my current mail folder and re-synchronize completely.

Then, after creating the folder to store mail in, simply running mbsync mail synchronizes my email! Simple as!

Hopefully this might be useful to somebody who made the same mistake of using offlineimap first before isync.