# Email Filtering

You can easily setup mail filtering via the web interface to the departmental mail system. Any filters you put in place will run as messages arrive independent of any email client you choose to use.

## Filtering out suspected Junk Mail/Spam

### Default Spam Filter Rule

By default each account has an initial filter rule in place that filters junk/spam messages into a separate folder called Junk. All mail from outside the department passes through the university's mail relays where it has tags added which indicate whether it is suspected spam and give the message a spam score. It is this spam score that the default spam filter uses. It is filtering any mail that is given a spam score of 5 or more into the separate folder, "Junk".

This type of spam scoring system typically has no learning mechanism (beyond software upgrade) so if a message is misclassified there is nothing to immediately correct the error for subsequent similar messages.

Should you wish to modify this spam filter rule or deactivate it:

1. Login to the web interface for the mail system https://zimbra.maths.ox.ac.uk
2. Click on the preferences tab
3. In the preferences window that appears click on Filters from the list on the left under Mail.
4. You will now see the list of filter rules on your account. The default spam filter rule is called "Spam Filter":
• You can untick the box next to a rule to deactivate it.
• To delete a rule simply select it and click the delete filter button.
• To modify a filter rule select it and then click the edit filter button.
The spam score of a message is shown by a number of stars, the more stars the more spammy the message is. The default spam rule uses 5 stars, to make the rules stricter reduce the number of stars or to make it less strict add stars.

## Filtering other messages

You may wish to filter all sorts of other messages as they arrive to make them easier to review. You can setup further filter rules as follows:

1. Login to the web interface for the mail system https://zimbra.maths.ox.ac.uk
2. Click on the Preferences tab
3. In the preferences window that appears click on Filters from the list on the left under Mail
4. You will now see the list of filter rules on your account and add additional rules
5. Click on New Filter to create a new filter rule.
6. The add filter window now appears in which you need to give your new filter a name and then using the drop down menus setup a rule. For example, you may wish to filter all messages which contain a certain word in the subject into a specific folder. You would do this by adjusting the drop down menus such that the settings read

If any of the following conditions are met: Subject contains my chosen words. Perform the following actions: File into folder Folder Name

You can of course make the rule filter on different message headers or on several headers together etc so the rule can be as simple or as complicated as you like. In this way you can build up several filters that are run in the order you specify (by clicking on the filters in the list and using the move up/down buttons to reorder them). In general after a rule makes a successful match no further rules are processed so one often has the spam rule first and then other rules follow.