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How does Pulsant's spam filtering work?

The Pulsant spam scanning system uses a program called SpamAssassin to detect spam coming into your mailbox. SpamAssassin detects spam emails by having a large database of rules which help to work out how likely a message is to be a spam.

Each rule has a score attached to it and when a message matches a rule, the score for that rule gets added to the total for that message. For example, the rule “HTML_20_30 BODY” is applied if the message is 20% to 30% HTML and has a score of 0.5. The rule “BIZ_TLD URI” means that the message contains a URL in the BIZ top-level domain and has a score of 0.8. If a message matched both the “HTML_20_30 BODY” and “BIZ_TLD URI” rules then it would get a score of 1.3.

Neither of these items on their own automatically mean a message is spam, but the more there are, the more likely a message is spam. You can then decide what score you would like to be your cut-off point or threshold. Messages which are scored above your threshold are marked as spam and put in your Junk folder (available via webmail).
There are also rules which look at the headers of the email (the part that contains the To:, From: and Subject: fields along with details of the path the message took to get to you). These rules will look for things in the header that should not be there. For example, if the sender has attempted to fake some of their details or the sending host is on a RBL (Realtime Blackhole List – a list of servers which spammers are known to be working from).

The Pulsant system allows you to choose from three settings:

This allows you to pick the level that best suits the sort of email you get. If you have a very low tolerance for emails that might be spam, you should set your spam filtering level to high. This will block any messages with a score of 5 or above. However, you should keep an eye on your Junk folder to make sure you don’t have any real emails that have been marked as spam.
If there are individual email addresses which are being marked as spam and being put into your Junk folder then you can add these to your whitelist. A whitelist is a list of known good email addresses for which spam filter is never applied.
If you are seeing a large number of real emails being marked as spam, you may have your filter set at too high a level for the type of email you are receiving and you should try setting the level to medium or even low.

If you have any issues with spam filtering please contact Pulsant support at [email protected] or 0845 1199 999.