HowTo: Send Email from an SMTP Server using the Command Line

The SMTP (Simple Mail Transfer Protocol) is an Internet standard for electronic mail (Email) transmission across Internet Protocol (IP) networks.

This tutorial shows how to connect to SMTP mail server and send an Email using the ‘telnet’ command.

Step 1: Open a connection from your computer to an SMTP mail server

$ telnet smtp.domain.ext 25
220 smtp.domain.ext ESMTP Sendmail ?version-number?; ?date+time+gmtoffset?
  • smtp.domain.ext – Your mail server;
  • 25 – Default port for SMTP.

Step 2: Declare your domain name or IP-address

You can set local.domain.name or anything you want in ‘HELO’, because the server doesn’t check its authenticity, that is one of the drawbacks of this protocol.

> HELO local.domain.name
250 smtp.domain.ext Hello local.domain.name [xxx.xxx.xxx.xxx], pleased to meet you

Step 3: Set sender’s email

> MAIL FROM: sender@adress.ext
250 2.1.0 sender@adress.ext... Sender ok

Step 4: Set recipient’s email

> RCPT TO: recipient@adress.ext
250 2.1.5 recipient@adress.ext... Recipient ok

Step 5: To write the message, type DATA and press ‘Enter’

> DATA
354 Enter mail, end with "." on a line by itself

Step 6: On the first line type ‘SUBJECT: Your Subject’ and press ‘Enter’ twice

> SUBJECT: Test message

Step 7: Continue typing your message

Hello,
this is a TEST message, 
please don't reply.
Thank you.

Step 8: Put a single period (.) on a line by itself and press ‘Enter’ to send your message.

> .
250 2.0.0 ???????? Message accepted for delivery

Step 9: Close the connection

> QUIT
221 2.0.0 server.com closing connection
0 (0)
Article Rating (No Votes)
Rate this article
Attachments
There are no attachments for this article.
Comments
There are no comments for this article. Be the first to post a comment.
Full Name
Email Address
Security Code Security Code
Related Articles RSS Feed
How to mount software RAID1 member using mdadm
Viewed 2202 times since Wed, Oct 3, 2018
Turbocharge PuTTY with 12 Powerful Add-Ons – Software for Geeks #3
Viewed 12237 times since Sun, Sep 30, 2018
RHEL7: Create and configure LUKS-encrypted partitions and logical volumes to prompt for password and mount a decrypted file system at boot.
Viewed 6753 times since Mon, Aug 6, 2018
ubuntu How to Reset Forgotten Root Password in Ubuntu
Viewed 1253 times since Tue, Dec 8, 2020
How to deal with dmesg timestamps
Viewed 1759 times since Wed, Oct 3, 2018
Red Hat Cluster Tutorial
Viewed 1358 times since Sun, Jun 3, 2018
Cron YUM How to use yum-cron to automatically update RHEL/CentOS Linux
Viewed 1648 times since Fri, Oct 26, 2018
LVM: Extend SWAP size by adding a new Logical Volume
Viewed 1282 times since Sat, Jun 2, 2018
Open SSL Encrypt & Decrypt Files With Password Using OpenSSL
Viewed 4209 times since Mon, Feb 18, 2019
How To Add Swap Space on Ubuntu 16.04
Viewed 1626 times since Fri, Jun 8, 2018