"Let's Encrypt" is an organisation that provides SSL certificates for free in an automated way. While the use is simple on IIS or Apache web servers, on Kerio Connect it is a bit more complicated as it comes with its own web server. Here is how I set it up (there might be other ways, of course, please feel free to add your comments at the bottom of the page).
First, download "letsencrypt-win-simple" from
This tool simplifies and automates Read more [...]
Find below a list of messages that can appear in the security log of Kerio Connect 8.0 and what they mean:
SMTP Spam attack detected from 18.104.22.168, client closed connection before SMTP greeting
This message only appears if Spam Repellent is switched on. It means that the client (sending mail server) hasn't waited the 25 seconds (or whatever is configured in Spam Repellent) for the SMTP greeting. It closed the connection too early. This is indicative of bot net Spam as normal mail servers would Read more [...]
In Kerio Connect, the filtering of personal mails is based on the filter language Sieve. As I didn't find many good samples in the Web, find below some interesting ones. I will update when I have new ones:
if allof (
header :contains "Subject" ["rma *","* rma","* rma *","rma"],
address :all :contains "Cc" "[email protected]
This copies any mails to the folder RMA that match the following criteria: The subject of the mail contains the word RMA and the mail has [email protected] Read more [...]
KMS (Kerio Mail Server) comes with the Spamassassin spam protection. Although not officially supported by Kerio, you can change spamassassin by modifying the spamassassin rules and config files. On Windows, all the important files are in
Before you change anything, you should definitely backup all files in this directory!
The .cf files contain the rules and the scores. They are plain text and you can change them, but you have to Read more [...]