Naming my Droplet | Naming Mail/Web Server (with consideration for PTR)

I’m currently following Ars Technica’s guide “Taking Email Back” and I need your advice. I have one class 1 TLS from StartSSL and it is for mail.bringlove.org. But StartSSL’s documentation says, “The base domain bringlove.org will be included by default in the Alt Name section.” I assume this means that both http://mail.bringlove.org and http://bringlove.org will be covered by the certificate. But how to plan for PTR?..

Considering PTR Records/Reverse Lookup, SPF Record, and things like DKIM, what would you name your droplet, mail.bringlove.org, or simply bringlove.org? This is a small personal website, and I’ll be hosting the site and the mail server in the same ubuntu-nginx/mariadb droplet. The most important thing to me is that my email be accepted by whoever I send it to, and with PTR in mind I know that it should make a difference how I name the server. And of course I don’t want the hassle and cost of segregating mail and site on different servers. It doesn’t help that I have no experience doing this, but I just don’t want to go through all this setup for nothing (again ;).

If you were me, with my goals and my TLS certificate, how would you name your droplet?