OfflineIMAP

CLIMail tool

Python program that syncs IMAP mailboxes with local Maildir folders in both directions.

OfflineIMAP downloads IMAP folders into local Maildirs and keeps both sides in sync, so a Maildir client can read mail offline. The maintained code base is offlineimap3, the Python 3 port; the original Python 2 repository is no longer developed. Configuration is an INI-style file, and Python helper functions can supply passwords, folder name mapping and filters.

Type: Mail tool
Interface: Command-line tools and prompts
Systems: Runs on Linux, macOS and BSD, on Windows through WSL. Not available for Android.
Language: Python
License: GPL 2.0 or later
Latest version: 8.0.3
Background: Python 3 port of the original OfflineIMAP (Python 2, no longer maintained)
Maintained: Yes
Website: offlineimap.org
Source: github.com/OfflineIMAP/offlineimap3
Documentation: offlineimap.org

Install

System	Support	Install
Linux	Native	apt`sudo apt install offlineimap3` dnf`sudo dnf install offlineimap` pacman`sudo pacman -S offlineimap` pipx`pipx install offlineimap`
macOS	Native	Homebrew`brew install offlineimap` pipx`pipx install offlineimap`
Windows	Through WSL	WSL`sudo apt install offlineimap3` No native Windows package; use WSL.
BSD	Native	FreeBSD pkg`pkg install mail/py-offlineimap` OpenBSD`pkg_add offlineimap`
Android	Not supported	-

Protocols and features

Protocols
Protocol	OfflineIMAP
IMAP	Yes
POP3	No
SMTP	No
JMAP	No
Maildir	Yes
mbox	No
notmuch	No

Features
Feature	OfflineIMAP
OpenPGP	No
S/MIME	No
OAuth2 sign-in	Yes
Threads	No
Search	No
HTML mail	No
Mouse	No
Multiple accounts	Yes
Offline use	keeps a full local Maildir copy
Calendar	No
Contacts	No
Vim-style keys	No
Configuration	~/.offlineimaprc or ~/.config/offlineimap/config (INI)

Pros and cons

Pros

Built-in XOAUTH2 support for Gmail and similar providers
Python hooks (pythonfile) for passwords, folder name mapping and filtering
Can sync accounts in parallel and run repeatedly with autorefresh

Cons

Slower than isync on large mailboxes
Older guides and some packages still point to the unmaintained Python 2 version
Only IMAP and Maildir; no POP3 and no sending

Use OfflineIMAP with Forward Email

How OfflineIMAP fits with a Forward Email mailbox. Replace you@example.com with your alias and the password command with your own. The same settings work with any provider once the server names change.

~/.offlineimaprc

[general]
accounts = forwardemail
pythonfile = ~/.offlineimap.py

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

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

[Repository forwardemail-remote]
type = IMAP
remotehost = imap.forwardemail.net
remoteport = 993
ssl = yes
sslcacertfile = OS-DEFAULT
remoteuser = you@example.com
remotepasseval = get_pass("forwardemail/you@example.com")

# ~/.offlineimap.py
# import subprocess
# def get_pass(name):
#     return subprocess.check_output(["pass", "show", name]).decode().splitlines()[0]

Protocol	Server	Port	Security
IMAP	`imap.forwardemail.net`	993	SSL/TLS
POP3	`pop3.forwardemail.net`	995	SSL/TLS
SMTP	`smtp.forwardemail.net`	465	SSL/TLS
SMTP	`smtp.forwardemail.net`	587	STARTTLS

Username: your full alias address, such as you@example.com. Password: the one shown by Generate Password next to the alias in your Forward Email account. Folders: INBOX, Drafts, Sent Mail, Trash, Spam and Archive.

Prefer no config at all? Forward Email's terminal app signs in with your account and has mail, calendar and contacts in one program.

Questions

Does OfflineIMAP work on Windows?

Not natively. It runs in Windows Subsystem for Linux (WSL). No native Windows package; use WSL.

Does OfflineIMAP support IMAP?

Yes, OfflineIMAP connects to IMAP servers directly.

Is OfflineIMAP open source?

Yes, under the GPL 2.0 or later.

How do I use OfflineIMAP with Forward Email?

Use the config in the Forward Email section on this page, saved as ~/.offlineimaprc, and replace the address and password with your own.

Sources

Edit this page on GitHub Report a mistake