Best opensource collab software

[heymrdj]

I want the best free open source collab software to run. I need email, calendar, and upload (file storage) mainly. Running without WebDav is preferred, as i don't really need the support. Running with mobile support is nice as well.

Looking at Zimbra open source, egroupware, phpgroupware, and Horde. Anyone with recommendations?

 

[heymrdj]

Oh and please move this if it really ain't the right spot...thanks mods