Currently, Mailbird does not support the CalDAV protocol, but it is on our roadmap.
While our development team is working on delivering support for the CalDAV protocol which will allow you to sync your calendar using CalDAV, we would like to count on your support for it so that it is implemented even sooner.
Simply click on the link below to let us know that you would like to use the CalDAV protocol in Mailbird:
While we are sorry that this is not possible at present, rest assured that every vote counts as part of our development roadmap, so we appreciate the time you will take to vote for this feature.