You do know they stopped developing this in 2012 don't you?
The legal company I last worked at used this for all staff, all 400 of them. Shocking!
I moved everyone over to O365 or Thunderbird depending on their role. More secure, better options, better support and just nicer to use.
You're leaving yourself open to any security vulnerabilities found as they won't be patched out.
Please stop using it.