Spam Folder: Difference between revisions

Latest revision as of 10:47, 18 December 2023

When connecting to our email service over IMAP we will create a special folder named spam (lowercase). If you delete the spam folder it will be re-created next time you log in.

Some email clients recognise this folder as being 'special' and may call it something else, e.g. our webmail calls it Junk

The service will then move messages that have been classified as spam into this folder (unless you are doing your own Sieve filtering). This helps keep your inbox free of spam and you should keep an eye on this folder in case there are messages that are not spam.

Some email clients (e.g. K-9 Mail for Android) refuse to notify the user of new mail in the Spam folder. This behaviour can be corrected by declaring (e.g. in the account's folder settings) that there is no special Spam folder.

Disabling the spam folder

To stop the mail system from putting spam (or any) messages then you can create an allow list for your address on the Control Pages.

Spam 'learning'

Our spam checking system performs many checks on a message to decide whether it is spam or not. One of the checks it can do, is to compare the message with previous messages -this is called Bayesian Learning.

Checking the learning

If you view the 'headers' of a message, you should see the spam report, and a line looking like:

 -3.0 BAYES_00               BODY: Bayes spam probability is 0 to 1%

or perhaps

 0.8 BAYES_50               BODY: Bayes spam probability is 40 to 60%

Here you can see the 'Bayes spam probability' as a percentage. In the first example the Bayes really thinks the message is not spam - it says 0-1%. The second example is less sure about it.

Teaching the system

If the 'Bayes spam probability' is incorrect, then it can be taught about messages that it has got wrong in the following ways:

Move a message OUT of the spam folder to tell the system it is NOT spam
Move a message IN to the spam folder to tell the system it IS spam

If you make a mistake, just move the message back.

The process of learning doesn't guarantee that the system will be correct next time a similar message is received, but it should help and you should see a change in the 'probability' in the headers.

Legacy folders

In the past we used to have a system that used folders called learnham and learnspam - this system is no longer used. These folders can be removed.

@@ Line 1: / Line 1: @@
 <indicator name="Faults">[[File:Menu-emailadd.svg|link=:Category:Email_Features|30px|Back up to the Email Features Category]]</indicator>
-When connecting to our email service over IMAP we will create a special folder named spam (lowercase). If you delete the spam folder it will be re-created next time you log in.
+When connecting to our email service over IMAP we will create a special folder named <code>spam</code> (lowercase). If you delete the spam folder it will be re-created next time you log in.
+Some email clients recognise this folder as being 'special' and may call it something else, e.g. our webmail calls it <code>Junk</code>
-The service will then move messages that has been classified as spam in to this folder. This helps
+The service will then move messages that have been classified as spam into this folder (unless you are doing your own Sieve filtering). This helps
 keep your inbox free of spam and you should keep an eye on this folder in case there are messages
 that are not spam.
+Some email clients (e.g. K-9 Mail for Android) refuse to notify the user of new mail in the Spam folder.  This behaviour can be corrected by declaring (e.g. in the account's folder settings) that there is no special Spam folder.
+==Disabling the spam folder ==
+To stop the mail system from putting spam (or any) messages then you can create an allow list for your address on the Control Pages.
+==Spam 'learning'==
 Our spam checking system performs many checks on a
 message to decide whether it is spam or not. One of the
 checks it can do, is to compare the message with previous
-messages. -this is called Bayesian Learning.
+messages -this is called Bayesian Learning.
+==Checking the learning==
+If you view the '[[Email_Viewing_Headers|headers]]' of a message, you should see the spam report, and a line looking like:
+  -3.0 BAYES_00               BODY: Bayes spam probability is 0 to 1%
+or perhaps
+.8 BAYES_50               BODY: Bayes spam probability is 40 to 60%
+Here you can see the 'Bayes spam probability' as a percentage.
+In the first example the Bayes really thinks the message is not spam - it says 0-1%. The second example is less sure about it.
 ==Teaching the system==
-If our system is marking non-spam messages as spam, and not marking spam messages, then one way to improce this is
+If the 'Bayes spam probability' is incorrect, then it can be taught about messages that it has got wrong in the following ways:
-to teach the Bayesian Learning system about messages that have been miss-classified. This is done in the following ways:
-*Move a message '''OUT''' of the spam folder to tell the system it is '''NOT''' spam
+*Move a message '''OUT''' of the spam folder to tell the system it is '''NOT spam'''
-*Move a message '''IN''' to the spam folder to tell the system it '''IS''' spam
+*Move a message '''IN''' to the spam folder to tell the system it '''IS spam'''
 If you make a mistake, just move the message back.
-The process of learning doesn't guarantee that the system will be correct next time a similar message is received, but it should help.
+The process of learning doesn't guarantee that the system will be correct next time a similar message is received, but it should help
+and you should see a change in the 'probability' in the headers.
+==Legacy folders==
-==Checking the learning==
+In the past we used to have a system that used folders called <code>learnham</code> and <code>learnspam</code> - this system is no longer used. These
-If you view the 'headers' of a message, you should see the spam report, and a line looking like:
+folders can be removed.
-  -3.0 BAYES_00               BODY: Bayes spam probability is 0 to 1%
-or perhaps
-.8 BAYES_50               BODY: Bayes spam probability is 40 to 60%
-Here you can see the 'Bayes spam probability' as a percentage.
 [[Category:Email Features]]
+[[Category:Email How to]]