コマンドラインから smtp が機能しているかどうかを確認する方法 (Linux)

telnet を使用して postfix やその他の SMTP をテストする唯一のことは、コマンドと構文を知っている必要があるということです。代わりに、swaks を使用してください :)

[email protected]:~$ 
[email protected]:~$ mail -f Maildir
"/home/thufir/Maildir": 4 messages
>    1 [email protected]                   15/553   test Mon, 30 Dec 2013 10:15:12 -0800
     2 [email protected]                   15/581   test Mon, 30 Dec 2013 10:15:55 -0800
     3 [email protected]                   15/581   test Mon, 30 Dec 2013 10:29:57 -0800
     4 [email protected]                   15/581   test Mon, 30 Dec 2013 11:54:16 -0800
? q
Held 4 messages in /home/thufir/Maildir
[email protected]:~$ 
[email protected]:~$ swaks --to [email protected]
=== 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:<[email protected]>
<-  250 2.1.0 Ok
 -> RCPT TO:<[email protected]>
<-  250 2.1.5 Ok
 -> DATA
<-  354 End data with <CR><LF>.<CR><LF>
 -> Date: Mon, 30 Dec 2013 14:33:17 -0800
 -> To: [email protected]
 -> From: [email protected]
 -> 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.
[email protected]:~$ 
[email protected]:~$ mail -f Maildir
"/home/thufir/Maildir": 5 messages 1 new
     1 [email protected]                   15/553   test Mon, 30 Dec 2013 10:15:12 -0800
     2 [email protected]                   15/581   test Mon, 30 Dec 2013 10:15:55 -0800
     3 [email protected]                   15/581   test Mon, 30 Dec 2013 10:29:57 -0800
     4 [email protected]                   15/581   test Mon, 30 Dec 2013 11:54:16 -0800
>N   5 [email protected]                   15/581   test Mon, 30 Dec 2013 14:33:17 -0800
? 5
Return-Path: <[email protected]>
X-Original-To: [email protected]
Delivered-To: [email protected]
Received: from dur.bounceme.net (localhost [127.0.0.1])
    by dur.bounceme.net (Postfix) with ESMTP id 52D162C3EFF
    for <[email protected]>; Mon, 30 Dec 2013 14:33:17 -0800 (PST)
Date: Mon, 30 Dec 2013 14:33:17 -0800
To: [email protected]
From: [email protected]
Subject: test Mon, 30 Dec 2013 14:33:17 -0800
X-Mailer: swaks v20130209.0 jetmore.org/john/code/swaks/
Message-Id: <[email protected]>

This is a test mailing

New mail has arrived.
? q
Held 5 messages in /home/thufir/Maildir
[email protected]:~$ 

たった 1 つの簡単なコマンドです。

[[email protected] tmp]# mail -v [email protected]
Subject: Test
Hello world
Cc:  <Ctrl+D>

[email protected] 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:<[email protected]> SIZE=46
250 2.1.0 <[email protected]>... Sender ok
>>> RCPT To:<[email protected]>
>>> DATA
250 2.1.5 <[email protected]>... Recipient ok
354 Enter mail, end with "." on a line by itself
>>> .
250 2.0.0 q7NEneju002633 Message accepted for delivery
[email protected] Sent (q7NEneju002633 Message accepted for delivery)
Closing connection to [127.0.0.1]
>>> QUIT
221 2.0.0 piwik-dev.example.com closing connection

telnet を使用して未加工のネットワーク接続を確立するための構文は次のとおりです:

telnet {domain_name} {port_number}

のように SMTP サーバーに telnet します。

telnet smtp.mydomain.example 25

以下をコピーして貼り付けます

helo client.mydomain.example
mail from:<[email protected]>
rcpt to:<[email protected]>
data
From: [email protected]
Subject: test mail from command line

this is test number 1
sent from linux box
.
quit

注: 「。」を忘れないでください。最後に、メッセージの終わりを表します。「quit」行は、セッションを終了します。