I changed DNS for our main site to customize the domain, not realizing that would redirect the site to the CM login page. So I removed the DNS setting (we have't run any emails yet) and when I click on customize to delete that domain, it takes me directly to our site with this URL: http://www.cedarsprings.org/admin/customize/.
Any suggestions on deleting that mapping in CM?
OK, now I realized that everything I click pretty much goes to the domain. I'm stuck now.
The mapping isn't done on CM side, but on your DNS settings (the CNAME entry that redirect towards createsend.com). So after deleting the CNAME entry, it should goes back to normal (though DNS takes some time to propagate).
Once the domain redirection is deleted (reverted back to DOMAIN.createsend.com), it should be ok. And actually, only a subdomain can be used to redirect to CM's admin...
Maybe I didn't understood the issue completely though. You might wanna contact support directly with this issue, to make sure.
We've talked directly via support, but for future reference you can always login using your original something.c/send.com URL and make changes there too.