Email Network Security Blog

The Non-Tangible Benefits of Email Filtering

The most tangible benefit to an off-site email filtering proxy service like Sentinare PostGuard is that users stop getting spam and viruses in their inbox– and your users will be very happy about that– but that is only 50% of the true benefit to using filtering service. By using an off-site email filtering service, you can configure your firewall to block inbound SMTP from the world, allowing SMTP traffic ONLY from the servers of the filtering provider. This greatly improves the security of your email server and local area network. Your MX records will be pointing to the filtering service and all your email will come from the servers of the filtering service company.

Be sure to configure your firewall to allow SMTP traffic only from their network. Otherwise you are missing 1/2 of the benefits of the filter. Then, the next time a nasty security bug comes along which requires that you patch your email server, you can do so at your leisure, since your mail server is not available to all the bad guys out there. You will be protected from the 24 by 7 attacks and probes hitting your mail server. If you think about it, there is really no more dangerous protocol than SMTP. Without an email filtering service, your email server is allowing connections from any SMTP client worldwide 24 hours a day. It then accepts data of unknown content from this unknown sender.

A good email filter service provider will also queue your mail when your server is down or the network is unavailable. This makes it even easier when you need to patch your email server. You can safely take down your server and your inbound mail will be held by the mail provider. Sentinare Messaging Solutions holds an unlimited amount of email for an unlimited amount of time.