Hi,
as per title, after installing Grafana, Grafana claims the main domain website e.g. my domain.com and automatically redirects to domain.com/login. After removing Grafana, the mail website shows 404 again.
Sorry type! mail is maiN
You should configure Grafana Host field with a dedicated host name, e.g. grafana.example.org.
From what I read it seems you entered the system FQDN that is already used by the Mail module.
In this case it is a wrong configuration.
You read it correctly, I typed it wrongly. I meant maiN website.
I don’t get the point. I understand that you installed Grafana and you configured it by setting the host FQDN.
In this case I expect Grafana holds the host FQDN (e.g. host.example.org): what’s wrong with that?
Recently we fixed the cluster-admin HTTP route to retain priority over such setting, so it is still accessible with an URL like https://host.example.org/cluster-admin, while any other HTTP path is served by Grafana.
What do you expect to see at domain.com? I guess it has an A or CNAME record pointing at ns7: why, if it’s the case? Define a HTTP route for it pointing somewhere else 
, I mean to another backend URL
I guess I need to re-read the docs, let me do that first 