You can back up Gmail users' mailboxes. A mailbox backup also includes the Calendar and Contacts data. Optionally, you can choose to back up the shared calendars.
The following items are skipped during a backup:
The Birthdays, Reminders, Tasks calendars
Folders attached to calendar events
The Directory folder in Contacts
The following Calendar items are skipped, due to Google Calendar API limitations:
Appointment slots
The conferencing field of an event
The calendar setting All-day event notifications
The calendar setting Auto-accept invitations (in calendars for rooms or shared spaces)
The following Contacts items are skipped, due to Google People API limitations:
The Other contacts folder
The external profiles of a contact (Directory profile, Google profile)
The contact field File as
What items can be recovered?
The following items can be recovered from a mailbox backup:
Mailboxes
Email folders (According to Google terminology, "labels". Labels are presented in the backup software as folders, for consistency with other data presentation.)
Email messages
Calendar events
Contacts
You can use search to locate items in a backup, unless the backup is encrypted. Search in encrypted backups is not supported.
When recovering mailboxes and mailbox items, you can select whether to overwrite the items in the target location.
Limitations
Contact photos cannot be recovered
The Out of office calendar item is recovered as a regular calendar event, due to Google Calendar API limitations