Use telnet to log on to the SMTP service and send an email (with authentication)

The number of emails sent in the past few days is small.ProgramBy the way, I checked why SMTP mail servers such as 126 and Gmail cannot use the SMTP commands in the lab class to send emails. At that time, based on the returned information, I only knew that the server needed identity authentication.

Today, I finally found out how to telnet to the SMTP server with identity authentication.

Provide a base64 encoded URL http://www.motobit.com/util/base64-decoder-encoder.asp

The specific process is as follows:
Microsoft Telnet/> open smtp.126.com 25
220 126.com anti-spam GT coremail System (126com [071018])
Helo mail.126.com
250 OK
Auth login // use the identity authentication logon command
334 dxnlcm5hbwu6
Kjihgfedcba ==/enter the username that has passed base64_encode.
334 ugfzc3dvcmq6
Abcdefghijk = // enter a password that has passed base64_encode ().
235 authentication successful
Mail from: <yaochengxiang@126.com> // tell the address of the server sender
250 mail OK
Rcpt to: <yaochengxiang@gmail.com> // tell the server recipient's address
250 mail OK
Data

354 end data with <CR> <LF>. <CR> <LF>
To: yourframe@162.com // recipient address displayed in the mail
From: Iamahacker@gmails.com // The sender address displayed in the message
Subject: Test mail // subject, and press ENTER twice

Hello yaos

. // End the transfer letter
250 mail OK queued as smtp14, f0cpbfsuzuovodwe. 10982s2
Quit // disconnect
221 bye
Connection closed by foreign host.

 

Status Code Description:

220: Service ready

250: The request email is correct and completed (Helo, mail from, rcpt to, quit command execution will return this message)

235: certified

221: Processing

354: Start sending data and end with. (This message will be returned if the data command is executed successfully)

500: syntax error. The command cannot be identified

550: The command cannot be executed, and the email address is invalid.

552: interrupt handling: the user exceeds the file space