End of SmartScreen Updates and how it Impacts IMF Tune

A couple of weeks ago Microsoft announced the end of SmartScreen updates. These updates feed the Exchange Content Filter agent to help it better identify new spam waves.

IMF Tune is designed to work in tandem with the Exchange built-in anti-spam agents. It requires the Exchange Content Filter to be enabled. Indeed IMF Tune waits for the Content Filter agent to process the email first, before performing its own filtering to establish the final spam classification.

In their announcement, Microsoft states that no new updates will be released after 1st November 2016. This is true for all Exchange version from 2007 to 2016. The Content Filter will still continue to work beyond November. It will work with the last SmartScreen update available on that date.

So how is this going to impact IMF Tune users?

IMF Tune is made up of multiple filters. The Content Filter provides us with one filtering result however this is not the only one. It is true that IMF Tune was born riding on the shoulders of the first Content Filter incarnation (the Exchange 2003 Intelligent Message Filter) but we didn't stop there.

With time we added many other filters including DNS IP Lists, URI filtering, Language filtering, Sender Auto-Whitelisting, Attachment filtering, various white/black lists and various rules. Furthermore we also encourage the use of other Exchange agents such as Sender ID and Sender Reputation. All of these work together to identify spam. So any degradation in filtering results is limited to one filtering stage.

The weight the Content Filter has on the final spam classification depends on the configuration. It is possible for IMF Tune to have all filtering stages disabled making it highly reliant on the Content Filter. However this is rarely the case. Users switch to IMF Tune because they need more filtering over and above what's available in Exchange.

It is fair to say that the limitations in the Content Filter, its inability to quickly respond to new spam waves (despite the updates) is what allowed IMF Tune to be here for over 10 years.

So what contribution is the Content Filter giving? The Content Filter does play a role in IMF Tune. We find it to be effective when dealing with traditional spam such as those selling pills, sex related spam etc. When it comes to fast changing spam, DNS IP Lists, URI filtering and Sender Reputation are much more effective.

So what impact does the end of SmartScreen updates is expected to have? Stopping the updates will accentuate further the inability the Content Filter has in dealing with fast changing spam. A weakness which we identified a long time ago and for which we have been developing counter measures.

What's next? The modality of how the updates are being discontinued for Exchange versions that are still under support, took us by surprise. However we believe IMF Tune users will hardly notice that updates went missing.

The Content Filter void can be filled. It involves technical solutions which we are capable of developing. We will make more information on future IMF Tune updates in the coming months, so please stay tuned.

Oh and by the way, we might need to rename IMF Tune.