Allows you to use msmtp offline by queuing email until you have an internet connection.

Features

• Runs as a daemon and (at a configurable time interval) attempts to send the mail in the queue directory.
• Drop-in replacement for msmtp in your mutt config.
• Only attempts to send the queued email message if it can connect to the configured SMTP server.
• When a new email message comes into the queue and you are already online, offlinemsmtp will send it immediately.
• Integrates with system notifications so that you are notified when mail is being sent.
• Disable/enable sending of mail by the presence/absence of a file. This is useful if you want to have some sort of "offline mode".

Installation

Using go install

go install github.com/sumnerevans/offlinemsmtp/cmd/offlinemsmtp@latest

Using Nix

Run ad-hoc:

nix run github:sumnerevans/offlinemsmtp

Using flakes:

{
  inputs.offlinemsmtp = {
    url = "github:sumnerevans/offlinemsmtp";
    inputs.nixpkgs.follows = "nixpkgs";
  };

  outputs = { offlinemsmtp, ... }: {
    // use the package: offlinemsmtp.packages."x86_64-linux".offlinemsmtp
  };
}

From source

git clone https://github.com/sumnerevans/offlinemsmtp
cd offlinemsmtp
go build -o offlinemsmtp ./cmd/offlinemsmtp

Run the daemon using systemd

Create a file called ~/.config/systemd/user/offlinemsmtp.service with the following content:

[Unit]
Description=offlinemsmtp

[Service]
ExecStart=/usr/bin/offlinemsmtp --daemon

[Install]
WantedBy=default.target

Then enable and start it:

systemctl --user daemon-reload
systemctl --user enable --now offlinemsmtp

Usage

offlinemsmtp has two components: a daemon that watches the outbox directory and sends mail when the network is available, and an enqueuer that adds mail to the send queue.

To run the daemon:

offlinemsmtp --daemon

To enqueue emails, use offlinemsmtp without --daemon. Pass msmtp arguments after --. Anything on stdin is forwarded to msmtp when the mail is sent:

offlinemsmtp -C ~/.msmtprc -- -t --read-envelope-from

Configuration with Mutt

Replace msmtp in your mutt configuration with offlinemsmtp:

set sendmail = "offlinemsmtp -a personal --"

Command Line Arguments

• -h, --help - show help and exit
• -o DIR, --outbox-directory DIR - outbox directory (default: ~/.offlinemsmtp-outbox)
• -d, --daemon - run the daemon
• -s, --silent - disable all logging and notifications
• -i INTERVAL, --interval INTERVAL - flush interval in seconds (default: 60)
• -C FILE, --file FILE - msmtp configuration file (default: ~/.msmtprc)
• --send-mail-file FILE - only send mail if this file exists
• -l FILE, --logfile FILE - write logs to file
• -m LEVEL, --loglevel LEVEL - minimum log level: trace, debug, info, warn, error (default: warn)
• Everything after -- is passed to msmtp

Contributing

See CONTRIBUTING.md.

Other projects

• https://github.com/marlam/msmtp-mirror/tree/master/scripts/msmtpqueue - included with msmtp, but fewer features.
• https://github.com/dcbaker/py-mailqueued - Python implementation.
• https://github.com/venkytv/msmtp-offline - Ruby implementation.