How to check if smtp is working from commandline (

Question

I have a SMTP-server, for the purpose of this question lets call it: smtp.mydomain.com.

How do i check if the SMTP-server is in working? Can I send emails from Linux commandline?

Answer 1

The only thing about using telnet to test postfix, or other SMTP, is that you have to know the commands and syntax. Instead, just use swaks :)

thufir@dur:~$ 
thufir@dur:~$ mail -f Maildir
"/home/thufir/Maildir": 4 messages
>    1 [e-mail]                   15/553   test Mon, 30 Dec 2013 10:15:12 -0800
     2 [e-mail]                   15/581   test Mon, 30 Dec 2013 10:15:55 -0800
     3 [e-mail]                   15/581   test Mon, 30 Dec 2013 10:29:57 -0800
     4 [e-mail]                   15/581   test Mon, 30 Dec 2013 11:54:16 -0800
? q
Held 4 messages in /home/thufir/Maildir
thufir@dur:~$ 
thufir@dur:~$ swaks --to [e-mail]
=== Trying dur.bounceme.net:25...
=== Connected to dur.bounceme.net.
<-  220 dur.bounceme.net ESMTP Postfix (Ubuntu)
 -> EHLO dur.bounceme.net
<-  250-dur.bounceme.net
<-  250-PIPELINING
<-  250-SIZE 10240000
<-  250-VRFY
<-  250-ETRN
<-  250-STARTTLS
<-  250-ENHANCEDSTATUSCODES
<-  250-8BITMIME
<-  250 DSN
 -> MAIL FROM:<[e-mail]>
<-  250 2.1.0 Ok
 -> RCPT TO:<[e-mail]>
<-  250 2.1.5 Ok
 -> DATA
<-  354 End data with <CR><LF>.<CR><LF>
 -> Date: Mon, 30 Dec 2013 14:33:17 -0800
 -> To: [e-mail]
 -> From: [e-mail]
 -> Subject: test Mon, 30 Dec 2013 14:33:17 -0800
 -> X-Mailer: swaks v20130209.0 jetmore.org/john/code/swaks/
 -> 
 -> This is a test mailing
 -> 
 -> .
<-  250 2.0.0 Ok: queued as 52D162C3EFF
 -> QUIT
<-  221 2.0.0 Bye
=== Connection closed with remote host.
thufir@dur:~$ 
thufir@dur:~$ mail -f Maildir
"/home/thufir/Maildir": 5 messages 1 new
     1 [e-mail]                   15/553   test Mon, 30 Dec 2013 10:15:12 -0800
     2 [e-mail]                   15/581   test Mon, 30 Dec 2013 10:15:55 -0800
     3 [e-mail]                   15/581   test Mon, 30 Dec 2013 10:29:57 -0800
     4 [e-mail]                   15/581   test Mon, 30 Dec 2013 11:54:16 -0800
>N   5 [e-mail]                   15/581   test Mon, 30 Dec 2013 14:33:17 -0800
? 5
Return-Path: <[e-mail]>
X-Original-To: [e-mail]
Delivered-To: [e-mail]
Received: from dur.bounceme.net (localhost [127.0.0.1])
    by dur.bounceme.net (Postfix) with ESMTP id 52D162C3EFF
    for <[e-mail]>; Mon, 30 Dec 2013 14:33:17 -0800 (PST)
Date: Mon, 30 Dec 2013 14:33:17 -0800
To: [e-mail]
From: [e-mail]
Subject: test Mon, 30 Dec 2013 14:33:17 -0800
X-Mailer: swaks v20130209.0 jetmore.org/john/code/swaks/
Message-Id: <[e-mail]>

This is a test mailing

New mail has arrived.
? q
Held 5 messages in /home/thufir/Maildir
thufir@dur:~$ 

It's just one easy command.

Answer 2

[root@piwik-dev tmp]# mail -v root@localhost
Subject: Test
Hello world
Cc:  <Ctrl+D>

root@localhost... Connecting to [127.0.0.1] via relay...
220 piwik-dev.example.com ESMTP Sendmail 8.13.8/8.13.8; Thu, 23 Aug 2012 10:49:40 -0400
>>> EHLO piwik-dev.example.com
250-piwik-dev.example.com Hello localhost.localdomain [127.0.0.1], pleased to meet you
250-ENHANCEDSTATUSCODES
250-PIPELINING
250-8BITMIME
250-SIZE
250-DSN
250-ETRN
250-DELIVERBY
250 HELP
>>> MAIL From:<[e-mail]> SIZE=46
250 2.1.0 <[e-mail]>... Sender ok
>>> RCPT To:<[e-mail]>
>>> DATA
250 2.1.5 <[e-mail]>... Recipient ok
354 Enter mail, end with "." on a line by itself
>>> .
250 2.0.0 q7NEneju002633 Message accepted for delivery
root@localhost... Sent (q7NEneju002633 Message accepted for delivery)
Closing connection to [127.0.0.1]
>>> QUIT
221 2.0.0 piwik-dev.example.com closing connection

Answer 3

Not sure if this help or not but this is a command line tool which let you simply send test mails from a SMTP server priodically. http://code.google.com/p/woodpecker-tester/

Answer 4

Telnet to your smtp server like

telnet smtp.mydomain.com 25

Syntax :

telnet {smtp_domain_name} {port_number}

And copy and paste the below

helo your_domain.com
mail from:<test@your_domain.com>
rcpt to:<to_email@your_domain.com>
data
From: test@your_domain.com
Subject: test mail from command line

this is test number 1
sent from linux box
.

Note : Do not forgot the "." at the end which represents the end of the message

I found this on the web, and added this to Stack Overflow as many end up here.