Fake Mail Commands Generally, following commands will work fine: helo mail from: someguy@random.com rcpt to: someotherguy@anywhere.com data content of email . quit Entering those commands when connected via telnet to a Sendmail daemon will send someotherguy@anywhere.com an email containing “content of email” from someguy@random.com. In some cases, you might need to type “helo random.com” at beginning (random.com being domain of return address) to get this to work. The return and to addresses, as well as content of e-mail, can be modified as much as you want. If it doesn’t work, daemon might need authentication, or syntax might be different (try adding <>s on either side of email addresses). And, backspace does not work, even though it looks like that. If you mess up in typing a command and press backspace, command is void. In contents of e-mail, backspaces will show up as boxes when read by receiver. This is an invaluable social engineering technique. Imagine sending an email to an AOL customer, faking return address as a system administrator, with contents something like “We are debugging system lost all our user data for your area. We require you to send your name, date of birth, address, username, password, credit card number, and credit card expiration date.” They would happily comply, thinking you were someone you weren’t. You are not completely anonymous when using this technique. Anyone who is serious about safety should know about email “headers,” or information included in email. If you have pop3 enabled with your email (you do if you have gmail) then just open up mail with Thunderbird (of Outlook, ugg) and tell it to display headers. I will not go in depth on this, but a search on internet will show you what you need to know to spot fake mail.