Unified Technology Solutions

Review: Off-site Mail Filtering

Spam is a major problem all businesses must deal with, but if you are running your own mail server the troubles you face are much worse. Even if your current filtering software prevents you from seeing the spam and viruses in your inbox, your internet connection and server still have to handle all that spam. How much spam are we talking about? Currently spam is 80%+ of all email traffic on the internet, this means for every email you receive that 4 spam messages are processed by your server, though I’ve seen some clients with 10 times that amount. All this spam still has to travel over your limited internet connection so it can be filtered out at the server and can cause other internet based services to slow down drastically.

The second problem spam causes for those hosting their own E-mail server is the cost to purchase software to filter both spam and viruses (yes they are usually separate software), not only do you have to pay for the service, but you have to pay someone to maintain and update it regularly. New viruses and spam techniques come out daily, so it is very possible the virus showing up today didn’t even exist when you updated last week, or even yesterday.

The third major issue I hear about is that businesses are finding out the email they send is being blocked by the receivers server. This is often caused by overzealous filters that give higher spam rankings to email coming from IPs assigned to Cable and DSL  ISPs (Internet Service Providers) like Comcast and AT&T. Unfortunately these services produce a higher level of spam then the higher grade services like T1s. Many off-site filtering services also offer outbound filtering services, this makes the E-mails appear to come from their servers instead of your own, also it makes sure you do not find your mail server blacklisted because one PC got infected with a spambot or other related malware.

The last issue is what happens to mail if your server or internet connection goes down?

So how does it work?

To set up off-site filtering your domain address (@something.com) is set up so mail is sent to the filtering service instead of directly to your server. The filtering service will run the e-mail through multiple filtering software packages to look for both viruses and spam, multiple software packages are used to reduce the chances that a single software will not have the virus in it’s known virus database. The actions taken after that are configurable to meet your needs, but the most common are that all virus emails are filtered out then the E-mail is given 1 of 3 spam rankings. Email ranked “not spam” is forwarded through the service to your mail server and shows up in your mailbox in second. Email ranked “probably spam” is sent to quarantine, once there the user will receive a daily e-mail letting them know they have mail to review and they can click directly on a link to release the email, add the sender to your safe list, or delete the email for good. The 3rd ranking is “definitely spam”, this is spam coming from known spam servers or matching known spam patterns, and is immediately deleted by the service.

Outbound filtering does the same in reverse, filtering your outbound e-mail to make sure your server has not been hijacked and is being made to send spam, also you can set up filters to make sure employees do not send out e-mails with racial, derogatory, or curse words that can reflect bad on your business. You can even add a company wide legal claim to all outgoing e-mail if needed, this is much easier then keeping every E-mail client updated with the latest legal disclaimer every time it needs to be changed for those companies that want or are required to have one.

Filtering service also adds a layer of protection if your server or internet access goes down, especially in a disaster. Email will be spooled on the off-site filtering servers and sent to your server when it comes back online, and you can access it from any internet connected PC if an important email is needed immediately.

Because of economy of scale often off-site filtering, with all it’s added features, is right around the cost of your current filtering software if not less expensive, with rates under $3.00 per user/month and requires little to no regular maintenance. This is very cost effective compared to on-site filtering software, and can be especially inexpensive if you are maxing out your available bandwidth and are considering the purchase a higher rate or second connection, often these are not needed after filtering is set up as we have seen users cut their used bandwidth as much as half.

UTS recommends and sells off-site filtering service by McAfee, a world leader in information systems and security research. To find out more and see if off-site filtering may be right for you feel free to contact us by email at sales@unifiedtechs.com, or give us a call at (772) 539-7667.