The spam filtering that is included with our hosting is good, but not a match for the quantity and complexity of spam being sent every day. For us, cleaning up email was taking too much time and we needed to find a better approach.
We have personally been using/testing a much more robust spam filter service for over a year, and have managed to cut down on our spam very dramatically.
Here are our results for the last quarter of 2014.
Total emails sent to us: 25,299
What typically gets marked as a ‘False Positive’ or spam is subscriptions to Old Navy, Amazon, etc – actual retail subscriptions – but very rarely does legitimate email get marked as spam.
We also have the ability to ‘white list’ domains that you do a lot of business with to ensure that all their emails get through.
Let me know if you’re interested in adding this extra layer of spam filtering to your email.il.