This article provides help on what can be done if the Spam Blacklist function is blocking legitimate emails from external users.
Please note that Kerio Connect pulls the information from the Blacklists set by the Admin directly from the service provider (e.g SpamCop, SpamHaus, SORBS). If their sender's domain/IP address was blacklisted by a particular service.
Nothing much can be done about that from Kerio Connect's end. However, the Blacklist function can be customized as per our article Email Spam Protection using Blacklists and Whitelists:
- You can choose which external Blacklists to use with the ability to add more lists or remove existing ones as well as choosing which ones are enabled/disabled
- You can also choose if a particular Blacklist will outright block the email or just add score (you can also set how much score) to their message's total
- If you choose to configure the lists to only add Score, you can also adjust the scores needed for tagging/blocking the emails
- Aside from that, you can create a custom Blacklist or a custom Whitelist (using an IP address list/group)
- Furthermore, you can override the blacklists by applying configurations described in Excluding an Email Address From a Blacklist
Note: If the problem persists, please add custom rules as described in Custom whitelists are not overriding the Spam Filter
You need to tinker with the settings to find the sweet spot that works best for you.