How to send an email using sendmail command in linux [closed]

Using sendmail command

Created a file with email content:

$ cat /tem/email.txt

Subject: Terminal Email Send

Email Content line 1
Email Content line 2

Now send email using the following command:

$ sendmail [email protected] < /tem/email.txt

Using mail command

$ mail -s "Test Subject" [email protected] < /dev/null

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

$ mail -a /opt/file.sql -s "Backup File" [email protected] < /dev/null

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

$ mail -s "Test Email" [email protected],[email protected] < /dev/null

Using mutt command

$ mutt -s "Test Email" [email protected] < /dev/null

Send an email including an attachment:

$ mutt -s "Test Email" -a /opt/backup.sql -- [email protected] < /dev/null

MTAs (Message Transfer Agents) like sendmail expect email messages in Internet Message Format. Usually it is better to use a MUA (Message User Agent) (e.g. mail), unless the message is trivially simple.

A "sendmail look alike" command is provided also by MTA/SMTP servers (postfix/exim/…) and programs like msmtp. Basic sendmail command line options are the facto standard so it may be a good choice for sending simple emails.

You may try the following shell script

#!/bin/sh

# sendmail command line optons:
# -i - do not treat lines starting with dot specially
# -t - read recipients lists from message headers: TO,CC,BCC
# -v - use verbose mode (describe what is happening) 
#
# The empty line separates mail headers from mail body.
# Without -t recipients should be listed after command line options.

FROM='[email protected]'
TO='[email protected]' 
/usr/sbin/sendmail -i -t << MESSAGE_END
To: ${TO}
From: ${FROM}
Subject: Example Subject

Hi, this is my message, 
and I'm sending it to you! 
MESSAGE_END

WARNING:
Sending text emails with non US-ASCII characters in email body requires extra headers (MIME). Another special encoding is required for non US-ASCII characters in email headers. See RFC 2045 and related for further details.

I'm surprised nobody has mentioned it here but I've been using swaks for this for years. I only came here because I had forgotten the name and expected to find it recommended.

Swaks is in debian and has a home page here.

I normally use it like.

swaks --from $EMAIL --to $TESTADDR --server $TESTSERVER

It has options also to test auth etc, so is quite handy in more complex situations too.