Ask HN: Email for startups?
Which is the go to service for email and calendar stuff for startups? Still Google Apps? Office 365? Some other third option? If your team are all Apple users (in part), the Apple calendar is pretty good for sharing. We use different email apps, but our email's provided by Media Temple as our hosting's with them. I rate Airmail pretty highly if you've got a Mac. Google Apps works like a champ.
We do use Trello's calender features for some stuff as well because we can link to tasks we've got set up within Trello itself.