SPAM filtering on the Crystallography Email system


The Crystallography email servers the SpamAssassin ( and MailScanner ( packages to scan messages for spam content.

Messages which are obvious spam ( SPamAasassin score > 8 ) are marked by inserting extra header lines and pretending the text {Spam?} to the subject line.



  1. It is possible for a genuine email to be, marked as SPAM. Although this is hopefully a very rare event.
  2. It is a personal decision by each user of the system as to whether they ignore or act on this spam marking.
  3. This spam tagging service is provided without guarantees or warranties of any kind. Birkbeck College does not accept any responsibility or liability for messages which an individual chooses to ignore or delete as a result of this spam marking.


If having read and agreed to the above you which to make use filter your email based on these SPAM tags , then there are two possible approaches.

  1. Server based filtering
  2. Client based filtering

Server Based Filtering

With server based filtering messages marked as SPAM are moved to a SPAM-FILTER at the time of arrival. This is completely independent of the email client.

The advantages of this approach include:

  1. Less work for the server and email client
  2. With less spam in the inbox email clients should login to the server quicker

To user server based SPAM filtering use your email client to create the email folder SPAM-FILTER

Once this exists the email server will automatically place any new messages tagged as spam in it.

These SPAM-FILTER folders will be periodically renamed and a new empty SPAM-FILTER folder created.

The folders will be renamed to SPAM-FILTER.1 SPAM-FILTER.2, SPAM-FILTER.3, SPAM-FILTER.4 and then deleted.


Depending on how your email client is configured you may need to create the folder

 mail/ SPAM-FILTERor create SPAM-FILTER under the mail folder /directory.


Client based filtering

It is also possible to configure some email clients to automatically filter messages. Each client has its own way of configuring email filters.

While client based filters may allow more flexibility then the server based method above however its disadvantages include the following:

  1. requires more work to configure each email client to filter the messages
  2. The email server and client have to do more work to store and then filter the messages
  3. With more messages in the inbox to scan and then filter the client may take longer to login to the email server 


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$Revision: 1.1 $      $Date: 2009/09/21 14:31:02 $