Comment by flashmob

Nowhere on the website it says that it's an anonymous email service provider - it was an anti-spam email solution first and foremost. In fact, the email sending feature prominently warned the user that their IP address would be included in the headers of the email sent. (The sending feature was not for anonymous email, but for the rare chance that a user needed to send an email from there or reply. Guerrilla Mail is mostly used for receiving)