5 Efficient Ways to Send Emails from the Linux Command-Line

mails play a crucial role in modern communication, and while services like Gmail, Yahoo, and RediffMail offer user-friendly web interfaces, there are times when sending emails directly from the command line is necessary. This guide introduces various methods to send emails from the Linux command line, ideal for integrating into shell scripts, cron jobs, and more.

Here, we explore several command-line methods for sending emails, focusing on the most popular choices among users. Choose any of the following methods to efficiently send emails from the Linux command line.

1. Using ‘sendmail’ Command

Sendmail, a widely used SMTP server in Linux/Unix systems, allows email sending via the command line. Follow these instructions to use the ‘sendmail’ command:

First, create a file with the email content:

cat /tmp/email.txt 

Subject: Terminal Email Send

Email Content line 1
Email Content line 2

The Subject line will be used as subject for the email.

Now send email using the following command.

sendmail user@example.com  < /tmp/email.txt 

Read more: Install and Configure Sendmail on CentOS/RHEL

2. Using ‘mail’ Command

The ‘mail’ command is a popular choice for sending emails from the Linux terminal. Here are some examples:

mail -s "Test Subject" user@example.com < /dev/null 

• -s is used for defining subject for email.

Also, you can send an attachment with this command. Use -a for mailx and -A for mailutils.

mail -a /opt/backup.sql -s "Backup File" user@example.com 

• Here -a is used for attachments. Use -A for debian based systems, which uses mailutils package.

You may face issue: Bash: mail: command not found

Also, we can add comma separated emails to send the email to multiple recipients together.

mail -s "Test Email"  user@example.com,user2@example.com < /dev/null 

3. Using 'mutt' command

Mutt is basically used for reading emails from Linux terminal from local user mailboxes, also useful to read emails from POP/IMAP servers. Mutt command is little similar to mail command. Use few of below examples to send an email.

mutt -s "Test Email" user@example.com 

Send an email including an attachment

mutt  -s "Test Email" -a /opt/backup.sql user@example.com < /dev/null 

4. Using 'SSMTP' Command

sSMTP allows users to send emails from SMTP server from Linux command line. For example to send an email to user admin@example.com use following command. Now type your subject of the email as below with keyword Subject. After that type your message to be sent to the user, After finishing your message press CTRL+d (^d) to send the email.

ssmtp admin@example.com 
Subject: Test SSMTP Email
Email send test using SSMTP
via SMTP server.
^d

Read more: How to Setup SSMTP Server on Linux

5. Using 'telnet' Command

As per my experience, all system administrators use telnet command to test remote port connectivity test or login to the server remotely. Most of the newbie in Linux doesn't know that we can send email using telnet also, which is the better way to troubleshoot email sending problems. Below is an example of email sending.

Red marked text is the user input and remaining is the responses of that commands.

telnet localhost smtp


Trying 127.0.0.1...
Connected to localhost.localdomain (127.0.0.1).
Escape character is '^]'.
220 fbreveal.com ESMTP Sendmail 8.13.8/8.13.8; Tue, 22 Oct 2013 05:05:59 -0400
HELO yahoo.com
250 tecadmin.net Hello tecadmin.net [127.0.0.1], pleased to meet you
mail from: sender@tecadmin.net
250 2.1.0 sender@tecadmin.net... Sender ok
rcpt to: myemail@ymail.com
250 2.1.5 myemail@ymail.com... Recipient ok
data
354 Enter mail, end with "." on a line by itself
Hey
This is test email only

Thanks
.
250 2.0.0 r9M95xgc014513 Message accepted for delivery
quit
221 2.0.0 fbreveal.com closing connection
Connection closed by foreign host.

Bonus Tips - Attach a file to Email from Shell

You can also send email with a attachment from Linux shell. Use -A option to provide a file path with mail command.

mail -s "Test Mail" -r mail-from@example.net -A attach.zip mail-to@example.com 

Conclusion

Sending emails from the Linux command line can be a huge time-saver for those who work extensively in terminal environments. Whether it's through simple commands like mail and mutt, or more complex methods using sendmail or telnet, there's a solution that fits every need. Mastering these methods can significantly enhance your efficiency and broaden your command-line skills.