Understanding Email Spam Score


To identify and filter out spam messages, mail servers rely spam filters. Spam filters run an assortment of criteria in a checklist which they use to determine an overall view on the validity of incoming mail.

The main criteria a spam filter looks for is whether the email is in HTML format, if it includes any unsupported HTML code such as scripts and forms, whether embedded images are present along with any formatting and coding errors.

A spam filter also checks the header and email body content to identify common spam phrases like "This is not spam!", spam words like “free”, any reference to money, as well as the sender information to ensure the name and email address are valid and have not been seen in emails previously labelled as spam. In addition to these checks, Bayesian filtering, DNS block list (DNSBL) checks, and collaborative filtering databases such as Razor are also often used by spam filters such as Spam Assassin.

SpamAssassin is incorporated onto the TotalSend platform, which is one of the most popular sets of spam filtering used today, to analyse all outgoing messages. SpamAssassin checks your email’s content against its list of rules and algorithms to determine if a message is spam before you hit the send button. A hit on any of the criteria is assigned a score, which is then used to calculate a combined score. This is called the email’s spam score.

The elements of the email are analysed and scored, which when combined gives a total spam score. This score is based on elements in your mail that have been flagged for spam. In the content spam score test, you don’t want to achieve high marks - the aim is to get the lowest score you can. The higher the email spam score rate is, the more checks you failed and the more likely your email is to be sent to the junk folder.

Content spam score testing is like a dress rehearsal before opening night. These tools analyse email messages to determine the likelihood of a campaign being blocked by spam filters before your mail gets sent out, so you have a chance to address and correct any of problems your email campaign may have. As we already know, when creating these messages, even the best marketers can make mistakes that result in their hard work being sent straight to the subscribers' spam folder rendering the email essentially pointless.

If your content spam score is above 5 it means that you will have to rework the email campaign aggressively and interrogate your application of plain text and html design, as well as check the sender name and address, to avoid it landing in the junk folder as a score of 5 is a guaranteed way to be marked as spam.

But take heart valued email marketers; there is a way to avoid this type of disaster from ever happening to you. The SpamAssassin results will highlight which rules on the checklist your email has failed and rank these according to relevance. You should correct the issues that are hitting you hardest by first correcting the problems generating higher scores, and then recheck the message. Continue to work through issues until you reach a good overall spam score. You don’t have to reach a zero score, but aim to attain a score of around 0.2 or lower. It is also possible to get a negative score and this would help you immensely to get inboxed but usually requires that you are whitelisted on well-known spam filters. Here is a full list of SpamAssasin’s tests with links to their explanations and parameters.

SpamAssassin is actually just a useful tool to help reduce the odds of sending your hard work into the junk mail folder, by using the  email spam score checker to identify and rectify content-related errors before you hit send. Emails that are technically well-constructed, contain legitimate content and are sent to recipients who have opted to receive them, are unlikely to be flagged as spam. Check out our comprehensive list of dos and don’ts to avoid email blacklisting.

So while no one wants to be branded as a spammer, you shouldn't fret about it too much. Like SpamAssassin writes on their wiki, “The rules catch spam. If your email isn't spam, you shouldn't be matching the rules. Even if you do hit an occasional rule, unless your email actually is spam, it shouldn't score high enough to be a problem.”