Vyte has an easy CalDAV integration that will let you connect your Mailbox.org calendar to Vyte. With this integration booking appointments on a Mailbox.org calendar will be super easy. You'll also be able to easily schedule meetings with Mailbox.org and Vyte.

To add your Mailbox.org calendar to Vyte you will need 3 pieces of information:
   1. Your server: https://dav.mailbox.org/caldav
   2. Your username: that will be your mailbox.org email address
   3. Your password: that will be your mailbox.org password

Once you have gathered these 3 items, you can add your Mailbox.org calendar to Vyte as a CalDAV calendar by following this tutorial: Connect a CalDAV calendar to Vyte