Blinkenshell provides Email accounts for all registered members. The address format is: username (at) blinkenshell.org and it's enabled by default.
SMTP access is also available but you have to authenticate in to be able to send mail. It's the same username/password as for logging in via Webmail/IMAP. You have to use a secure connection (TLS) to be able to authenticate.
If you want, you can set a forward address. Just execute the following command on the shell echo "email@example.com" > ~/.forward or just edit the .forward-file by hand.
You can also use this account to send Email from your web applications. Remember to authenticate with SMTP or it will not work!
Using this service to send spam is strictly forbidden and will get your account suspended!