Can't change hostname or FQDN on Ubuntu 14.04 LEMP droplet

When I set up the droplet (for lack of an imagination at the time), I set the name to “main”. I have one droplet, so that seemed fairly logical. So I set up root ssh access and type “hostname” and it gives me “main”. Same deal when I type “hostname -f”. Well, I’m trying to set up Exim4 to send mail from my Django app (I only need to send, not receive) and I added “127.0.1.1 main.mydomain.com main” and “<myip> main.mydomain.com main” to /etc/hosts. I then executed “service hostname restart” and “hostname -f” only returned “main”. I even rebooted (something I try to avoid doing) and it still comes back “main”. Not sure why this is…

I’m guessing, but I’m not 100% sure, that’s why when I use the command “echo test message | mail -s test email@email.com” I’m not getting an email at email@email.com (too many emails???). If it isn’t absolutely necessary to have hostnames set up to use exim or sendmail (does anybody know if sendmail is installed by default on Ubuntu LEMP droplets), I’d like to avoid it because its caused me such a headache.

Any help will render me eternally grateful to your apparent awesomeness.