Thank you for this explanation, this is most welcome to understand how things in nethserver works.
However the reason I bring this to the attention is because I first had nethserver provided with a Let’s Encrypt certificate and with testing from NextCloud with e-mail links they were default send with a https link. This is of course for safety reasons. If you subsequently integrate NextCloud into Webtop and send an e-mail link from Webtop the link is in http.
And if I understand correctly now I can solve this difference with executing the following command in order to record it in the nethserver so that it will be fixed in the configuration?
config setprop webtop PublicUrl https://mail.publicdomain.com/webtop