Kerio Connect includes different methods and tests to detect and block spam emails. These methods and tests are as follows:
IP Black/White Lists
This method uses the IP address groups to block automatically, increase the spam score, or allow all messages originating from the IP on the list. This is configured under Spam Filter > Blacklists.
IP Address Groups help easily define who has access to, for example, remote administration, services, and are used in additional settings in Kerio Connect like Blacklist/Whitelist.
"Caller ID for e-mails: The Next Step to Deterring Spam" is the Microsoft's draft specification to address the widespread problem of domain spoofing. Domain spoofing refers specifically to the use of someone else's domain name when sending a message, and it is part of the larger spoofing problem, the practice of forging the sender's address on e-mail messages.
Caller ID for e-mails would verify that each email message originates from the internet domain it claims to come from. Eliminating domain spoofing will help legitimate senders protect their domain names and reputations, and help recipients more effectively identify and filter junk email. Caller ID requires the authorized IP address to be defined in the DNS configuration called a TXT record.
Below is a Caller ID record for the teamaviola.com domain as our example:
<ep xmlns='http://ms.net/1'><out><m> <r>188.8.131.52</r> </m></out></ep>
This means that only the IP
184.108.40.206 is authorized for the domain. If a Kerio Connect server, with Caller ID enabled, receives an email from this domain, Kerio Connect will verify if the originating IP is authorized by checking the DNS records of teamaviola.com. Depending on the settings, it can block the message, increase the Spam score, or just log it in the Security log.
NOTE: IP Address Groups can also be excluded from Caller ID check.
You can check which IP is authorized for a certain domain by going to Caller ID.
- Securing Kerio Connect
- Antivirus and Content Filters
- Sender Policy Framework Filter
- Anti-Spam Advanced Filter
- Securing the SMTP Server