On 14.10.22 16:13, Marc wrote:
I also do not want any other other 'crap' just the cal (and card) dav solution.
sorry about my suggestion, but I am just a big fan of SOGo (no affiliation with) from sogo.nu ... it may not be a solution for you because it offers caldav, carddav, webmail, but performance is top notch, maybe you want to have a look anyway