So before today, if you tried to register for Hmail with a subdomain, i.e.

the "Set your records instantly" button would try to take you to namebase.io/domain-manager/sebastian.rasor instead of just rasor. Anyways, today I fixed that. In addition if you already have an MX record set, the "Set your records instantly" button won't try to create another MX record, and if you have a valid SPF record, it won't try to create another SPF record.