When messages are sent to a Distribution Group, and a user in that group has a vacation Auto-reply set up, Kerio will respond to the group address, and the auto-reply will be triggered again, and a loop results.
In order to avoid this, another mail filter is required. To set this up:
1) Log into Kerio Web Mail, and click on Settings, and then Mail Filters
2) Click “New” to add a new rule.
3) In the Conditions pane, check the box for “Where the recipient address (To or CC line) contains
4) In the Actions pane, check the box for “Stop processing more rules”
5) In the Rule Description pane, click the underlined value (in this case ‘contains”’), and enter the name of the distribution group (for instance, email@example.com)
6) Name the rule something descriptive, and click “OK” to save the rule.
7) In the Mail Filters window, single-click on the rule you just created, and click the “Move Up” button until that rule is above any other rules that would cause messages to be sent to the group. In most cases, you should just move it to the top.
Step 7 is important – if this rule is below your Out Of Office rule, it will trigger too late.