What I want here is simple, but I'm not really sure how to approach it. I have a tournament website based on WordPress, where users sign up for a tournament by commenting on a post.
The problem is, that then I need to send all those guys an email, which means I have to look up 50+ emails for users every single time. I'm thinking of doing some kind of JOIN on the comments and users tables, but I don't really know how to put this in WordPress.
I read somewhere, that if I want to add stuff for users, it should be in a theme, and if I want to add it for administrators, it should be as a plugin, but this looks like it could be a simple script put somewhere.
How would you solve this?