mailctl provides IMAP/SMTP clients with the capabilities of renewal and authorization of OAuth2 credentials.

Many IMAP/SMTP clients, like msmpt, fdm, isync, neomutt or mutt can use OAuth2 access tokens but lack the ability to renew and/or authorize OAuth2 credentials. The purpose of mailctl is to provide these missing capabilities by acting as a kind of smart password manager. In particular, access token renewal happens automatically in the background transparent to the user.

If an IMAP/SMTP client cannot even use an OAuth2 access token itself it still may be "wrapped" with fdm and msmtp with the help of mailctl.

mailctl also has some functionalities to manage the orchestration of a mailing system comprised of msmtp, fdm, and (neo)mutt or similar ones.

If you are using fdm with no complex desktop system you might also be interested in my mailnotify program which generates pop-up notifications about incoming email messages.

mailctl has been successfully used with Google/Gmail, operation with other Oauth2 service providers are planned.

Before mailctl is fully operational you need to create the necessary configuration files. See details in Configuration. Make sure that all the directories referenced in the configuration exist.

After configuration the very first command you must run is authorize. That is an interactive process involving a browser since during it you need to login and authorize access to your email account. mailctl will lead you through this process.

mailctl -h generates this help message:

mailctl - Provide OAuth2 renewal and authorization capabilities.

Usage: mailctl [--version] [-c|--config-file <config>] [--run-by-cron] [--debug]
               COMMAND

  Mailctl provides IMAP/SMTP clients with the capabilities of renewal and
  authorization of OAuth2 credentials.

Available options:
  -h,--help                Show this help text
  --version                Show version
  -c,--config-file <config>
                           Configuration file
  --run-by-cron            mailctl invoked by cron
  --debug                  Print HTTP traffic to stdout

Available commands:
  password                 Get the password for email
  access                   Get the access token for email
  renew                    Renew the access token of email
  authorize                Authorize OAuth2 for service/email
  fetch                    Get fdm to fetch all or the given accounts
  cron                     Manage running by cron
  list                     List all accounts in fdm's config
  printenv                 Print the current Environment

If no configuration file is specified the default is $XDG_CONFIG_HOME/mailctl/config.yaml.

More detailed help for individual commands can also be generated, for example:

% mailctl authorize -h

Usage: mailctl authorize <service> <email>

  Authorize OAuth2 for service/email

Available options:
  <service>                Service name
  <email>                  Email address
  -h,--help                Show this help text

Shell completion for bash, zsh and fish shells are provided.

The authorization process of Organizational/Institutional accounts can slightly be different from of individual accounts and that might cause the authorization to fail. That is definitively the case for Google.

When you invoke mailctl to authorize an account like this below:

mailctl authorize <service> <email>

the program takes you to a login page at the given <service> and derived from the <email> address. In the case of [email protected] that could be a different login page from the "normal" login page. The solution is to invoke authorization like:

mailctl authorize <service> <company>

where <company> is just a name not a complete email address. Then simply pick the right account on Google's login page. Since now the only usage of <company> here is for the name of the .auth file mailctl will create you just need to pick something that makes sense and doesn't interferes with your other accounts.

The various functionalities of mailctl are quite loosely coupled. Choose, that is configure, only the ones you need. For details on your options, see configs/config-template.yaml.

The configuration files for mailctl are in YAML. The files in the configs/ directory are templates for mailctl, msmtp and fdm. The configs/services-template.yaml file contains details for google, microsoft and yahoo.

You need to provide your own client_id and client_secret of your application or of a suitable FOSS registered application.

Service providers varying how they communicate at their authorization and token endpoints. The accepted HTTP methods and how the request's parameters delivered must be configured in the services.yaml file for both endpoints. Options for *_http_method are POST and GET. Options for *_params_mode are query-string, request-body (JSON encoded), request-body-form (x-www-form-urlencoded) or both. When both is configured mailctl uses the request-body method since it is considered safer.

If you encounter difficulties during authorization or renewal try to use the --debug switch which causes mailctl to mirror print HTTP traffic to stdout.

The Oauth2 credentials are kept encrypted using GNU PG. so it is assumed that an authorized gpg-agent is running. Alternatives like gnome-keyring might be used.

fdm, if used, can be run by cron with a crontab like this:

PATH  = /YOUR_HOME_DIRECTORY/.cabal/bin:/usr/bin:/bin
# fetch mail in every 10 minutes
*/10 * * * *  mailctl --run-by-cron fetch

Each release contains a compiled static executable of mailctl which should work on most Linux distributions. You can download the latest one from here. Check the sha256 check sum of the downloaded file. Rename it to mailctl, made it executable and put somewhere in your search path.

For Archlinux users there is also a package on AUR: mailctl-bin

To build mailctl from source you need a Haskell development environment, with ghc 9.2.4 or higher. Either your platform package system can provide this or you can use ghcup. Once you have the ghc Haskell compiler and cabal etc. installed, follow the steps below:

Clone this repository and invoke cabal:

git clone https://github.com/pdobsan/mailctl.git
cd mailctl
cabal update
cabal install --install-method=copy

That installs mailctl into the ~/.cabal/bin/ directory.

All transactions and exceptions are logged to syslog. If your OS using systemd you can inspect the log with a command like below:

journalctl --identifier fdm --identifier mailctl --identifier msmtp -e

The method of dealing with OAuth2 services was inspired by the mutt_oauth2.py Python script written by Alexander Perlis.

mailctl is released under the 3-Clause BSD License, see the file LICENSE.