Overview

Kerio Connect service crashes and restarts on its own every minute. Users are logged out of their webmail accounts with every restart.

Prerequisites

• Kerio Connect installed on Linux OS (Debian, Ubuntu, CentOS)

Scenario 1

• MacOS client connected over Exchange Web Services protocol (EWS) using Outlook or native Apple Mail/Calendar applications experience intermittent and slow account performance issues.

Scenario 2

• Kerio is connected to an external network device for archiving/backup purposes, using nfs4

Diagnosis

Scenario 1

A user on a Mac connected over Exchange Active Sync creates new schedules on the Apple Calendar, and one of the schedules crashes the service. The calendar appointment may contain URLs that become duplicated.

The problem might generate the below error line in the dmesg log at the moment of the crash:

mailserver[24470]: segfault at 0 ip 000000000188f5ce sp 00007f1824a977c0 error 4 in mailserver[400000+3012000]

Scenario 2

Kerio Connect uses for Archiving and Backup an external storage (a NAS device, for example), which is mounted with nfs4. The below errors will be showing up in the dmesg log every time that the server wants to access the NAS device, and subsequently, everytime the server crashes:

nfs4_reclaim_open_state: Lock reclaim failed

Solution

Scenario 1

Delete the Exchange Account on the affected Mac and use Webmail or Kerio Connect Client on mac instead.

1. Open macOS Settings -> Internet Accounts.
2. Select the Exchange account -> click minus sign (-) to remove the account.
   
3. Confirm the deletion by clicking OK.
   

Scenario 2

1. Confirm the presence of a nfs4 mount, run the mount command in Linux Terminal; if there is such a device connect, it would show up like this:
   
2. Run umount <device_path> to unmount the device
3. Troubleshoot the external storage device separately, and reconnect it once the connection to it is working correctly

Testing

Monitor the Kerio Connect service, which should not crash anymore.