Are there any limitations to the calendar functionality in OnMail?
Day view is the only sorting option for OnMail's mobile apps, however week/month views are coming in a future update.
Meeting room locations are not supported at this time.
There is a limit of one alert per event at this time.
Intelligent link/app integrations and/or extensions (such Zoom, Google Meet, etc) aren't supported at this time, but are indeed part of our product roadmap.
"RSVP" is not supported in v1 - events are automatically added, and must be removed from calendar if you wish to remove or redo unwanted/plans change. However, the ability to specify your RSVP with a Yes, No, or Maybe response will be coming in the near future.
Your OnMail calendar cannot be added to third-party calendar apps at this time.