Fighting Spam

At Net Virtue, we’re constantly trying to find new ways of providing a better service to our customers. One of the major points raised by our customers is RBL (realtime black list) issues and finding appropriate ways of mitigating the risk. While we haven’t had many cases of servers being listed on RBL’s, we wanted to help reduce the effects on RBL listings to improve email delivery.


We’ve been investigating techniques, software and hardware solutions to assist with this problem and we’ve implemented the following:


1. Automatic authentication relay blocking when more than 100 emails are sent from outside of Australia. About 30% of spam that is sent from our servers is done via authenticated (knowing your username and password) relay. The new system automatically detects that it’s likely a compromised login and automatically resets your email password and sends an email to advise that it’s been compromised with steps on how to correct the issue in future (using SSL encryption).


2. We’ve installed firewall devices to help filter spam messages that are sent outbound and discard them should it hit a high score, or the destination server be listed on an RBL. We’ve set the values on this server to a value which is great for blocking known spam and blacklisted domains however lets legitimate email go through without a problem. This also allows us to have multiple sending IPs which allows us to remove an IP from the pool should it become blacklisted.


All our servers are currently being rolled out to this new platform and we’re excited to finally stamp out potential future issues with RBL listings.


We are one of a handful of service providers that are offering this service and it’s all free of charge.