Greetings,

In case Az. 7 O 80/07, the District Court of Lüneburg has ruled that the use of blacklists for mail filtering is an illegal process. The court thereby confirmed the view of a known spammer that the fact that mails from his servers were deleted by the SPAM filter was an act of censorship.

According to the ruling, the fact that a mail server is used to transmit soleily SPAM is not sufficient to block mails from it entirely. Blocking a single mail address would have been sufficient, according to the court. However, even this step would only have been acceptable in order to prevent an immanent danger of a virus attack.

According to a c't article, they seem to interprete it in the way that if you reject the mail during the smtp transaction, this ruling doesn't apply because you didn't delete the mail (you never accepted it = it was never successfully sent from the sending mailserver).

The article also stated that it was the case of an ISP blocking the IP.

So if you allow your customers to define which blacklist they want to use and which not or if you put all the spam into a separate folder (and thus not delete it after the smtp transaction was successfully completed), you should be fine.

Regards

Jean-Pierre