I am trying to test a product that uses SMTP (or email messages) to communicate.
We've came accross some minor SMTP delivery issues (due to settings problem). We post binary to the SMTP message, which is the cause of the problem.
I am trying to build a testplan that covers SMTP configurations and negative SMTP testing.
I am still reading about this stuff, I appreciate any comments, specifically on how to trick SMTP.
There are only 10 types of people in the world: Those who understand binary, and those who don't
The commands for SMTP (as outlined in http://www.faqs.org/rfcs/rfc821.html) are all text based. The following set of commands would generate an email from Willy Wonka to Dogbert. (Note: you must first create a connection by telnetting to port 25 of the mailserver)
mail from: email@example.com
rcpt to: firstname.lastname@example.org
From: Willy Wonka
I think you're really funny so I'm sending you a lifetime supply of Everlasting Gobbstopers. (keep in mind that since they're everlasting, I'll only be sending one)
Now, the "helo" command is a greetings where you say where you're coming from. For testing, it's fun to say you're from some random location to see if it accepts what you say or does a reverse lookup. The mail from and rcpt to are self explanitory, but you can fake being anyone you enter as the mail from source. The data field can have anything as the body up 'till a single period on it's own line. This can include binary attachments, or HTML code. Other forms of testing can include mail bombs, email flooding, and virus transmittal. See what your mail application does with those too.
Hope this helps!
Christopher A Walters
Security/Performance/Software Architect email@example.com