使用telnet测试后缀或其他SMTP的唯一方法是,您必须了解命令和语法。相反,只需使用swaks :)
thufir@dur:~$ 
thufir@dur:~$ mail -f Maildir
"/home/thufir/Maildir": 4 messages
>    1 thufir@dur.bouncem                   15/553   test Mon, 30 Dec 2013 10:15:12 -0800
     2 thufir@dur.bouncem                   15/581   test Mon, 30 Dec 2013 10:15:55 -0800
     3 thufir@dur.bouncem                   15/581   test Mon, 30 Dec 2013 10:29:57 -0800
     4 thufir@dur.bouncem                   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 thufir@dur.bounceme.net
=== 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:<thufir@dur.bounceme.net>
<-  250 2.1.0 Ok
 -> RCPT TO:<thufir@dur.bounceme.net>
<-  250 2.1.5 Ok
 -> DATA
<-  354 End data with <CR><LF>.<CR><LF>
 -> Date: Mon, 30 Dec 2013 14:33:17 -0800
 -> To: thufir@dur.bounceme.net
 -> From: thufir@dur.bounceme.net
 -> 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 thufir@dur.bouncem                   15/553   test Mon, 30 Dec 2013 10:15:12 -0800
     2 thufir@dur.bouncem                   15/581   test Mon, 30 Dec 2013 10:15:55 -0800
     3 thufir@dur.bouncem                   15/581   test Mon, 30 Dec 2013 10:29:57 -0800
     4 thufir@dur.bouncem                   15/581   test Mon, 30 Dec 2013 11:54:16 -0800
>N   5 thufir@dur.bouncem                   15/581   test Mon, 30 Dec 2013 14:33:17 -0800
? 5
Return-Path: <thufir@dur.bounceme.net>
X-Original-To: thufir@dur.bounceme.net
Delivered-To: thufir@dur.bounceme.net
Received: from dur.bounceme.net (localhost [127.0.0.1])
    by dur.bounceme.net (Postfix) with ESMTP id 52D162C3EFF
    for <thufir@dur.bounceme.net>; Mon, 30 Dec 2013 14:33:17 -0800 (PST)
Date: Mon, 30 Dec 2013 14:33:17 -0800
To: thufir@dur.bounceme.net
From: thufir@dur.bounceme.net
Subject: test Mon, 30 Dec 2013 14:33:17 -0800
X-Mailer: swaks v20130209.0 jetmore.org/john/code/swaks/
Message-Id: <20131230223317.52D162C3EFF@dur.bounceme.net>
This is a test mailing
New mail has arrived.
? q
Held 5 messages in /home/thufir/Maildir
thufir@dur:~$ 
这只是一个简单的命令。