The SMTP Server → Filtering tab lets you set up filtering of messages going through the VPOP3 SMTP service. This may be incoming SMTP messages, or locally sent messages.
SMTP Rules let you create custom rules for processing messages as they go through the VPOP3 SMTP service.
The option Local SMTP Rules on each connection is usually turned off. If this is turned on, then VPOP3 will load the SMTP rules every time an SMTP session starts. This is useful if the SMTP rules are being modified by something outside of VPOP3. Otherwise, VPOP3 will only load the SMTP rules whenever they are modified from within VPOP3.
The Reload SMTP Rules button lets you manually reload the SMTP rules
SMTP rules are processed at various times during the SMTP transaction - at the MAIL FROM, RCPT TO and DATA stages. VPOP3 picks the appropriate stage to test the message depending on the fields being tested - for instance, if a rule checks only the 'return path', then it can be checked in the MAIL FROM phase, but if it checks a message header, it has to be checked during the DATA phase.
To edit the SMTP rules, press the Edit SMTP Rules button. This brings up the SMTP Rules list.
Each row in the rule list is a 'rule'. VPOP3 processes the rules in order, from top to bottom. When it finds a rule which matches the message, it will process that rule, then not process any more rules.
To add a new rule, press the '+' icon. To delete a rule, press the 'bin' icon next to the rule. To move a rule up or down in the list order, use the 'arrow' icons next to the rule.
Press the '+' to add a new rule, or click on the rule name to edit an existing rule
The Rule Name is a name for you to refer to the rule
The Rule Type is the action to perform when the rule matches:
If you want to copy/redirect a message to more than one address, you can use a Distribution List to do this
If you want to copy/redirect a message to a specific folder for a local user, you can use the format <username> <foldername>, eg bob Sent Items, which will copy the message to the 'Sent Items' folder for the user 'bob'.
You can tell VPOP3 to require all the conditions to match before triggering the rule, or to only require any one of the conditions
If no conditions are defined, then the rule will always trigger.
Press the green '+' icon to add a condition', or the red 'x' to delete a condition
Each condition will compare data about the message with some test data.
The data which can be checked are:
Note that you can NOT check the message body content (or attachments, etc) using SMTP rules
If you need to check the message body, or attachments, you may need to use a custom Spam Rule script