On Dreamost, running Nextcloud with sqlite3 storage, and a Let's Encrypt certificate.
I'm running php 7.0, and edited .php/7.0/phprc
to add the following line:
extension=fileinfo.so
On my phone I have both CalDAV-Sync and DAVdroid (also available through F-Droid running. I think I only need DAVdroid, but I had CalDAV-Sync first and it works so ¯_(ツ)_/¯
I use CalDAV-Sync to sync calendars/tasks and DAVdroid to sync contacts.
On my laptop, I sync calendars with vdirsyncer + khal, and sync addresses with vdirsyncer + khard. Mutt is now using khard to autocomplete addresses. I store my Nextcloud password in pass
Mutt and Offlineimap configs at: https://gist.github.com/amandabee/cf7faad0a6f2afc485ee