I've been using my firstname.lastname@example.org address for many years and of course, it's my adobe ID (long before I heard of BC) and I decided to move my website to BC. So imagine my surprise when it wouldn't let me set up my email address (never had a problem with any other hosts.) Because I needed to have this email back up and running as soon as possible, I went and switched my Adobe ID. Now I can't get into BC and I've got a site to switch over ASAP.
In this case please reach out to our chat support so we can assist with your login troubles.
http://helpx.adobe.com/contact/index.html (select business catalyst)
Our agents will be able to pull up your account and investigate further.