Enabling Horde/Atmail webmail interface
STEPS
1. Access your Plesk control panel at https://www.yourdomain.com:8443 [ Example :https://www.crmcell.com:8443 ]
2. Click on Subscriptions.
3. Click on the control panel of that subscriptions.
4. Click on Mail tab.
5. Click on change settings.
6. Choose the webmail interface as Horde or Atmail.
7. Click on ok.