title: General Guidance on Rails Mailers
body: <p>I am making an event registration tool in Rails and I am having trouble working out the mailing section. I am using Mailgun API and I've got a generic "Thank you for Registering" email working when the user signs up as well as a contact form submission that comes to my email. Part of the requirements for the application is the ability to send promotional emails (separate from Thank you for Registering emails). These promotional emails are more like (One week reminder) type emails. </p>
  
  <p>So these emails need to be able to be created by the admin setting up the event as this is a general purpose tool. So to save the emails the admin creates, I have a mailings object. So the relationship is a bit like this:</p>
  
  <p>Event has many mailers, registrations, etc. (and those belong to the event). They are nested resources because they are specific to an event. Now I need to bridge the gap of how to go from the mailers created by the admin to sending them to Mailgun. The problem is we will have to have the ability to add recipients because they may want to send to people besides the registrants for the event. So I need to go from the mailing#show (which shows a preview of the mailing and will need to be able to add/remove recipients), loop through all of the recipients, and send the message that is in the mailing.message field.</p>
  
  <p>I am so close to finishing this tool except for this mailing which I cannot wrap my head around. I see a lot of examples that create a mailer but I am not sure if that would work for me since the message are unique and it needs to get the message and subject from the mailer object. Any advice or guidance? I am really struggling to get this part done.</p>