postmaster.gmx.de
Postmaster MailSecurity (GMX, Postmaster Mailsecurity)Welcome to the GMX Postmaster site. At GMX careful evaluation of incoming emails and protection against unsolicited emails are top priority. This site provides both users and administrators with all the information they require on the subject of email and spam protection. Unsolicited email advertising causes substantial economic damage. Spam causes additional costs for email system operators. For example, they are forced to invest in more powerful hardware due to the increased volume of email.
http://postmaster.gmx.de/