[CMD][TELNET][EXCHANGE] SMTP Kommunikation mit Telnet Testen

Connect to the SMTP Server
C:>telnet <SMTP Server name or IP> 25
If the connection is successful you should receive the SMTP Server banner. It should look something like this and return the 220 code on the first line.
220 SMTPServer.testdomain.local Microsoft ESMTP MAIL Service ready at Sat, 8 Jan 21
10 6:03:15 –0600
If you receive output, try saying hello to the server with the ‘ehlo’ command.  After you press ENTER you should receive a list of available options on that particular SMTP server.  Take note of the line that reads ‘250-AUTH NTLM LOGIN’.  If you want to test authenticated SMTP, you need to have the ‘AUTH LOGIN’ command available.  AUTH LOGIN translates to basic authentication.  For instance, this server supports both NTLM and basic authentication.
ehlo
250-SMTPServer.testdomain.local Hello [192.168.127.10]
250-SIZE
250-PIPELINING
250-DSN
250-ENHANCEDSTATUSCODES
250-STARTTLS
250-X-ANONYMOUSTLS
250-AUTH NTLM LOGIN
250-X-EXPS GSSAPI NTLM
250-8BITMIME
250-BINARYMIME
250-CHUNKING
250-XEXCH50
250 XRDST
If you don’t see the option for ‘AUTH LOGIN’ check your SMTP server settings.  In Exchange 2007, you can open the Exchange management console, browse to Server Configuration, select Hub Transport, and then check the properties of the default receive connector.  In particular, check the authentication tab.  It should be something like this…


TLS
Basic
Exchange Server Auth
Integrated Windows Auth

Login to the STP Server AUTH LOGIN
334 VXNlcm5hbWU6
It’s important to note here that authentication in SMTP is done using Base64 encoded phrases.  So when I enter ‘AUTH LOGIN’ and press enter the server returns ‘VXNlcm5hbWU6’ which is Base64 for Username:.  Any and all parts of the authentication discussion will be in Base64.  I use this web site…
http://www.webpan.com/Customers/Email/base64_conversion.htm
to do Base64 encodes and decodes.  You can Google for a different method if you prefer.  Let’s do the entire authentication conversation in Base64 and then I’ll show the translated input and output.
Conversation in Base64
AUTH LOGIN
334 VXNlcm5hbWU6 YWRtaW5pc3RyYXRvcg==
334 UGFzc3dvcmQ6
cGFzc3dvcmQ=
235 2.7.0 Authentication successful
Translated back to plain text AUTH LOGIN
334 Username: administrator
334 Password:
password
235 2.7.0 Authentication successful
Once we receive the authentication successful response we can test sending a email as that particular user.  This is no different then sending a test email through telnet without the authentication piece.
Send the test email mail from:administrator@testdomain.com
250 2.1.0 Sender OK
rcpt to:user@mydomain.com
250 2.1.5 Recipient OK
data
354 Start mail input; end with <CRLF>.<CRLF>
This is a test email
.
250 2.6.0 <4b5125d60-e494-47f2-9917-7bd91e455544@SMTPServer.testdomain.local> Queued
mail for delivery