Spam Level Grows Above 99%
1 Feb 2010
You’ve all been there, you sit down at your desk Monday morning at 9am to see that you have 2,000 emails waiting to download and knowing that almost all will be advertising the latest genital enhancement or drug on the market. For our first entry on our new hosting blog I thought I would look at the current Spam rates we’re seeing across our network at the moment and how this is separated out. Over the coming weeks we’ll be going on to look at solutions to spam and things you can do to help win the war. As I sit here I’m watching the Swordfish Cisco Ironport Anti-Spam Appliance handle the tens of thousands of emails that pass through our system every hour I’m reminded that spam is here to stay for the time being at least. The highlights of our current rates of spam go like this:
- Current Spam Rate: 99.3%
- Current Clean Email Rate: 0.7%
For everyone that has downloaded hundreds of emails on a Monday morning this isn’t surprising at all but still for only 1 in 100 emails to be legitimate is frightening to say the least. What we have found interesting over the past few months at Swordfish is how this spam is being dealt with more and more. Out of the 99.3% spam which is entering our system 99.1% of it is being stopped based on it’s reputation alone. Reputation Filters For those of you new to filtering emails based on reputation it works in a fairly simple way. If you send an email from a legitimate mailserver that mailserver will have typical characteristics as it’s designed to be a legitimate source of emails. These characteristics include:
- It will adhere to SMTP standards of communications, header details etc…
- A reverse DNS lookup - in other words when the receiving mailserver checks information about the IP address of the sending mailserver it’ll resolve to a domain name.
- It won’t be listed on any blacklists (Well easier said then done!)
- It has a good reputation score with senderbase (in the cisco ironport scenario)
- Sending out emails to a specific domain slowly (as usually it will be you sending to a friend and so only one email is sent in a few minutes)
In a good number of cases where mailservers are receiving spam they are doing so via hacked machines or home user computers infected machines and so in all likelihood won’t have things like reverse DNS lookups or standard methods of communication from an authorised domain name and so is rejected out of hand. In addition the ironport reputation filter words by throttling incoming emails from suspected spam messages so as more spam comes in the more likely the ironport setup tags it as spam and rejects it. The great thing about reputation filters is because it’s checking the reputation of the sender and not the contents of the email it’s extremely efficient and consumes hardly any resources to do. So whilst our Ironport filter handles hundreds of thousands of emails a day only a fraction require anymore than a passing glance. Swordfish Hosting Anti-Spam For £2.00 per month per domain you can have our 99.3% spam detection rate for your personal or business email. Makes sense doesn’t it? Sign up for one of our great web hosting packages and get started now
