I am new user of mailcow !
I use Thunderbird as a mail client on desktop.
Since Thunderbird 91.x, carddav and caldav can be detected and be configured automaticaly.
Try with my server in direct LAN connection, that’s works (expection on the certicate because my mailcow don’t have a public IP).
But when I try throught the http proxy I use, it detect IMAP/SMTP etc, but don’t detect caldav/carddav.
My proxy use https only, try to redirect http also, not better still not detect automaticaly the cardav caldav.
If I manually and carddav and caldav URL after the autoconfigure process, I have access to it and that’s works.
It’s just a autodetection issue, but want to fix it for the users, is easyier that explain how to configure the calendar and addressbook manualy !
Does someone known how thunderbird detect carddav/caldav link ?