JMAP servers often contain contacts and calendars (and other items) as well as mail messages. when thinking about backing up my fastmail account, i'd say that backing up contacts is at least as important as backing up messages. calendar items and notes also seem important to me.
it appears the JMAP specs for contacts/calendars are becoming more stable, so the API may be in a place to make queries about these items and writing them out in the same way that we write messages.
messages in EML format are fairly standard, and that's what jmap-backup writes. the standards for other formats are not as clear. there's vCard for contacts (from CardDAV) and iCalendar for calendars (from CalDAV). what's unclear is whether the data provided by JMAP can be easily converted to these formats. both stalwart and fastmail support CardDAV/CalDAV, but as of this writing only fastmail supports JMAP contacts/calendars. stalwart say broader JMAP support is on the way.
JMAP servers often contain contacts and calendars (and other items) as well as mail messages. when thinking about backing up my fastmail account, i'd say that backing up contacts is at least as important as backing up messages. calendar items and notes also seem important to me.
it appears the JMAP specs for contacts/calendars are becoming more stable, so the API may be in a place to make queries about these items and writing them out in the same way that we write messages.
messages in EML format are fairly standard, and that's what jmap-backup writes. the standards for other formats are not as clear. there's vCard for contacts (from CardDAV) and iCalendar for calendars (from CalDAV). what's unclear is whether the data provided by JMAP can be easily converted to these formats. both stalwart and fastmail support CardDAV/CalDAV, but as of this writing only fastmail supports JMAP contacts/calendars. stalwart say broader JMAP support is on the way.