All emails which pass through the filtering system are evaluated against hundreds of different rules, each of which has a weighting based on the probability that the rule indicates spam. Each email is given a total score, with the score being the sum of all matched rules.
Your email administrator is able to specify the spam score which triggers an email to be tagged as spam and is also able to affect whether the subject line is changed or not – usually an email the system thinks is spam will have [spam] in the subject line. To find out why an email was marked as spam, you need to analyse the email headers and look to see which rules were triggered.
How to analyse email headers to find why an email is marked as Spam:
Follow these steps below to work out why an email was tagged as spam by the filtering system.
- Locate the email headers. See here for how to locate the email headers.
*Important: The headers must be copied from the original email as received by the person with the issue – forwarding a problem email will destroy the headers.
- Review the email header and look for the “X-Spam-Status:” header. Here’s an example:
X-Spam-Status: Yes, score=9.6 required=5
The above shows that the email scored 9.6 and that it’s considered spam because the required score for the domain is set to 5. The required score can be changed in the Spam Handling settings.
- Next, review the “X-Spam-Report” header which will show all of the spam filtering rules triggered by the email and the score assigned for each rule. Please note that some rules reduce an emails score by assigning a negative number. There’s a very brief description next to each rule to explain what it does.