I do not have access to webmail

I create mail@mydomain.com
I am trying to login mydomain:8090/rainloop to have access to webmail.
After writing mail@mydomain.com and password, I have this message: Domain is not allowed

Login with admin and check the domain settings. rainloop/?admin

Thank you #Pimmal. I’m administrator, but I don’t know how I check the domain settings. rainloop/?admin…
All emails from another domains it’s ok.