Take that, Spam!

courtesy of Flickr user @freezelightAs a midyear project, we wanted to determine the most common request/feedback we get from customers through our various support channels—phone, email, live chat, and even the public forum—and do what we needed to do from a technical support and server operations standpoint to address whatever that issue might be.

It was quickly apparent that one of the most common items had to do with spam, mainly the amount of it that was finding its way to customer inboxes.

The good news for customers is that the latest version of SmarterMail (version 6.x) comes with much more built-in support for combating spam, including a built in SpamAssassin engine and support for CommTouch, just to name a couple of the new features. However, as of this moment, most of our shared hosting customers are on SmarterMail 5.x mail servers (a segment wide upgrade to SmarterMail 6.x will be announced in the coming weeks). But in the meantime, we wanted customers on SmarterMail 5 to see an improvement right away.

What we did

One of the first things we wanted to do was implement a new RBL (Reputation Block List) from Barracuda that we’ve heard some great things about. But we needed to test it, and see what other changes we could make on top of the new RBL that would make the biggest impact for our customers.

Everyone likes to tell me about how great Gmail’s spam filtering is. I have a personal Gmail account, and I have to say I do get quite a bit of spam to it, although it’s typically filtered to the junk folder. It’s not perfect, but it does do a pretty good job.

Using my Gmail account as a point of reference, I signed up for an online survey that is known to be a front for spamming. I signed up using both my Gmail and SmarterMail accounts. As expected, within a couple of days both mail boxes were getting slammed with spam messages. On my Gmail account, a large majority (about 97%) of these messages were going to my junk mail folder. For my SmarterMail account, using our existing default spam settings, 100% of the messages made it to my inbox, but were marked as different levels of spam (i.e. Low, Medium, High).

This turned out to be a very good way to for us to understand the differences between what we do by default and what others do as a standard for their customers. I started going through the headers of the messages and realized that all the weights for real (non spam) messages were pretty low. So we started making adjustments to options, such as increasing the weight of Reverse DNS, Spamhaus, SPF, Domain Keys, etc. After making these adjustments (now as the default settings on the server) we saw that over 90% of the spam messages were now being tagged as a weight of medium or above, but still being delivered to the inbox.

So I cruised through about 150 messages looking at headers understanding the weights that each test had provided and found that these were accurate results.

What do we do now? I made an adjustment to the server settings for messages marked as “high” and “medium” to be moved to junk mail (those messages marked as “low” I still had sent to the inbox, but sill marked as “low” on the subject line). When I returned from a three-day weekend after making those changes, I logged in to my test mail box on the SmarterMail server and what did I find? Only one spam message found its way to my inbox, but a couple of hundred messages were in my junk mail folder.

What this means for you

Because of the great results we’re seeing with these new default spam settings and the implementation of the Barracuda RBL, we have begun deploying these changes to a few of our shared servers. We will, of course, send you notification once we’ve scheduled your mail server for the change.

It’s important to note that these new “default” settings will only affect those customers that do not use custom spam settings on their domain or user account.

If you’re interested in seeing the new settings, weights, and actions we will be implementing, take a look at our new KB article about it.

We look forward to continuing to improve the Spam Filtering options that are available, and are committed to making our email a service you will not have to worry about when hosting with us.

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2 Responses to “Take that, Spam!”

  1. With the new values set, can you say how much or what percentage of mail with a value 30 or higher was “legitimate” messages?

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  2. Hi Boogieknight, thanks for your response. I have throughout the years accumulated many email addresses of different ISP’s and domains on other mail host providers. I was able to forward and generate new email from accounts with no valid emails reaching a high score of 30. The score of 30 would mean a failure of multiple tests concluding that the message either strongly resembles unwanted advertising, is sent from a known source for spam and even combined with being sent from a mail server that is not setup to correctly send email.

    The BRBL (Barracuda) is a very intelligent source of known servers distributing Spam and Virus messages.

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