About spam

All incoming email is checked for spam.  Any mail which is clearly spam will be rejected and will never enter your mailbox.  However, I am often asked why some mails were not rejected, this page should answer these questions.

What is spam?

Spam is “Unsolicited Commercial Email”.  That is, any mail trying to sell you something from a company that you don’t know.

Adverts and newsletters from companies that you have bought products from is probably not spam, it is more likely that you have allowed them to email you by providing your details.  In these cases it is best to try and unsubscribe, or block the company from sending you mail.

A more thorough and sensible definition of spam is available on Brad Templeton’s website.

How is incoming email checked for spam?

A piece of software called SpamAssassin runs on the server.  It is free and does an excellent job of checking what mail is spam using the following techniques (and more):

  • Rules which check for common “spammy” features, for example the word ‘viagra’
  • Comparison against databases of known spam on the internet
  • Checks to see whether the computer sending the mail is known to be used by spammers

This software is not foolproof and can sometimes get it wrong, read on for more details.

Why do I still get spam?!

If you are still receiving undesired messages (and you have tried to unsubscribe) you have a number of options.  Tutorials are available which show how to reduce your spam threshold or block undesired senders.

Alternatively you may forward the whole message to David, who will invoke some wizardry and try to improve the spam detection so that it gets caught in future.