Security (* administrator only)
The options on this page allow you to enable spam filters, antivirus scanning, or black and white list rules in order to protect your system and Mail Server users.
Spam
Enable the options below to manage and avoid receiving junk mail.
To enable SpamAssassin spam filter:
- Check the box Enable SpamAssassin filter engine to filter out spam based on content-matching rules.
- Enter a number of days in the Delete spam interval field to specify when spam messages will be deleted.
- Click the SpamAssassin Settings button to see more options.
- Adjust the score which messages must exceed to be marked as spam (Low, 5; Medium, 7.5; High, 10).
- Specify custom text which can be added to the subjects of spam.
- Choose whether or not to report spam as an attachment encapsulated in a new message.
- Enable Auto learning or Auto white list to further improve spam filtering. If Auto learning is enabled, choose the spam score which messages must exceed to be added to the "learn as spam" database.
- Click the Custom Spam Filter button to create and manage rules to automatically mark certain messages as spam or non-spam. Rules that mark messages as non-spam take priority over rules that mark messages as spam.
- Click OK to save settings.
To enable DNS-based Blackhole List spam filter:
Enable DNS-based Blackhole List filter based on a list of IP addresses of computers or networks to filter out spam published through the Internet Domain Name Service.
- Tick Enable DNS-based Blackhole List filter.
- Click DNSBL Servers button to manage the list of DNSBL servers.
- Click Create and specify the Server and Server type. Click OK.
- Click Edit to edit the DNSBL server.
- Click Delete to delete the DNSBL server.
Antivirus
Enable antivirus to scan all incoming and outgoing messages for viruses. If an infected message is detected, the system will delete the message and notify the sender.
Black and White List
The Black and White List feature allows you to reject, discard, or allow certain messages based on various criteria, such as the sender, domain, or the mail client IP address. For example, you can create a rule to always reject messages sent from a certain email address (e.g. "menelaus@argos.com"), a domain (e.g. "argos.com"), or mail clients from a certain IP address ("192.168.123.456").
To create black and white list rules:
- Click the Black and White List button.
- Click Create.
- Specify the criteria for the rule.
- Choose what to do with messages that fit the criteria:
- Reject it: The message will not be sent from or received by Mail Server.
- Accept it: The message will be accepted whether or not it was blocked by the DNSBL list.
- Discard it: The message will be discarded. Mail Server will not inform the sender.
- Click Finish to save settings.
Rule Priority:
- Messages that match multiple types of rules are handled in the following order: IP address of mail client > Sender rules > Recipient rules.
- For example, there are the following two rules:
- IP address of mail client: 192.168.48.15 --> Reject it
- 'From:' address contains: username@mail.com --> Accept it
In this case, if a message is sent from "username@mail.com," but the IP address of the client that sent the message is "192.168.48.15," then the message will be rejected, because IP address of mail client rules have greater priority.
- Rules with matching content but different actions are handled in the following order: Reject it > Discard it > Accept it.