Wednesday, November 9, 2011 - 15:04
Janet(UK) recommends that you configure your Janet access router to block connections from Janet (and the rest of the Internet) to TCP port 25 (SMTP) of almost all IP addresses in your network. The addresses of a small number of mailers which are carefully managed and are not a relaying risk can then be released from the block; for a small organisation this may be a single IP address.
