I used my dyndns subdomain (from when they were free) to complete the cert on, and the mail address was jack@mail.randvids.tk. I had to edit out the tisbjj part of my subdomain (tisbjj.dyndns.org) to get the glue test to work. Did I do something shady or otherwise wrong, or is the above 100% rule compliant?
To add to this, I use randvids.tk for everything.
I run my own servers at 99.199.11.127 and 2001:470:1c:a3b::2 - one of them is an IRC server on port 17667.
randvids comes from the original aim of the domain, RANDom VIDeoS.
I run my own BIND setup at the aforementioned IPs.