msmtp

lightweight SMTP client for sending email from the command line

TLDR

Send email

$ echo "[message]" | msmtp [recipient@example.com]

Send email with subject

$ echo -e "Subject: [Hello]\n\n[Body]" | msmtp [recipient@example.com]

Send from specific account

$ msmtp -a [account_name] [recipient@example.com]

Test configuration

$ msmtp --serverinfo

Check account configuration

$ msmtp --configure [account_name]

Send file as message

$ msmtp [recipient@example.com] < [message.txt]

Print configuration

$ msmtp -P

SYNOPSIS

msmtp [-a account] [--serverinfo] [options] [recipients]

msmtp is a lightweight SMTP client for sending email from the command line. It works as a sendmail replacement, enabling scripts and applications to send mail through external SMTP servers.Configuration in ~/.msmtprc defines accounts with server settings, authentication, and TLS options. Multiple accounts can be configured for different mail servers or identities.Password handling supports several methods: plaintext (not recommended), passwordeval to run a command (e.g., password manager), or system keyring integration.TLS is supported via STARTTLS or direct TLS connection. Certificate verification can be configured to use system CA certificates or specific files.As a sendmail replacement, msmtp can be symlinked to /usr/sbin/sendmail, making it the default mail transport for the system. Many applications use sendmail for outgoing mail.Integration with mutt, git, and other tools is straightforward - they just need to know the sendmail path or can use msmtp directly.

PARAMETERS

-a ACCOUNT, --account ACCOUNT

Use specified account.

-f ADDRESS, --from ADDRESS

Set From address.

-C FILE, --file FILE

Use configuration file.

--serverinfo

Print server information.

-P, --pretend

Print configuration, don't send.

--configure ACCOUNT

Show account configuration.

-d, --debug

Debug mode.

-t, --read-recipients

Read recipients from message.

-X FILE, --logfile FILE

Log to file.

--tls

Use TLS encryption.

--tls-starttls

Use STARTTLS.

--host HOST

SMTP server host.

--port PORT

SMTP server port.

--user USER

Authentication username.

--passwordeval CMD

Get password from command.

CAVEATS

Requires SMTP server access. Password storage needs consideration. Some providers require app-specific passwords. TLS certificate issues may occur. Queue/offline sending requires msmtpd or msmtp-queue.

HISTORY

msmtp was written by Martin Lambers starting around 2000 as a simple sendmail replacement. It focused on being lightweight and configurable, supporting modern SMTP with authentication and TLS. The project remains actively maintained.