Tuesday, July 7, 2009

How can I test my SMTP service ?

You can use TELNET to test your SMTP service. SMTP uses port number 25, so in order to use telnet to open an SMTP session with an Exchange server we use the command

telnet test.server 25
If the connection is successful, we should see a banner and a command line interface. You may consult RFC 821 for SMTP commands,

220 test.server Microsoft ESMTP MAIL Service, Version: 5.0.2195.5329 ready at Mon, 15 Sep 2009 20:50:07 +0210
helo test.server
250 test.server Hello [192.168.0.101]
mail from: admin@test.com
250 2.1.0 admin@test.com....Sender OK
rcpt to: Sam@acc.net
250 2.1.5 Samp@acc.net
data
354 Start mail input; end with .
subject: test mail
Hi Sam,
I'm sending email using TELNET.
.
250 2.6.0 Queued mail for delivery
quit
221 2.0.0 test.server Service closing transmission channel
Connection to host lost.
Press any key to continue...

The above techniques can also be used for NULL sender identity check and SMTP Open Relay.
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1 comment:

  1. pjha21March 3, 2010 at 10:45 PM

    Dear Avijit Hi,

    I am Puneet Jha from NECHCL System Technologies.

    Our company is a joint venture between NEC Corporation Japan and HCL India and the company focuses on providing high quality and cost effective IT products and services.

    I got your mail address from your blog.

    At present we are studying about Web Application Security & various Application Firewalls and their relevance/effectiveness in application protection from hack attacks.

    We would like to have a discussion with you regarding the same over the telephone or e-mail.
    Could you be kind enough to please spare some time (around 5 to 7 minutes) from your busy schedule to provide us your contact number and your convenient time, so that we can have a discussion with you regarding the same.

    Regards
    Puneet Jha
    puneet.jha@nechclst.in
    http://www.nechclst.in/

    ReplyDelete

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