Sending malicious email as a test

I have set up a working SMTP relay together with MailScanner. This SMTP relay is not — and will not be — able to relay email from the outside, only local email.

Is it possible to send a malicious email with the terminal? I have googled around but could not find anything that could answer my question. For example, I want to use:

echo "{malicious-string}" | mail [email protected]

What could the "{malicious-string}" be?

Use the EICAR test virus. http://www.eicar.org/86-0-Intended-use.html

echo 'X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*' | mail 

Edit: Be sure to read Michael Hampton's as well!

To be sure, you should use the EICAR test virus, and attach it to the email, rather than simply putting it in the body.

echo -n 'X5O!P%@AP[4\PZX54(P^)7CC)7}$EICAR-STANDARD-ANTIVIRUS-TEST-FILE!$H+H*' > ducklin.docx
echo "Here is 10 million dollars" | mailx -a ducklin.docx [email protected]