Rails: why would I want more than one ActionMailer?

Reading the ActionMailer tutorial, I'm kind of confused by the need to create a named mailer (rails generate mailer UserMailer). Would I ever want more than one? Why isn't th开发者_C百科ere just a single global one?

Clearly I can just create a single mailer with an arbitrary name and get on with my life, but I'm worried that I'm missing something, ought I to be creating different mailers for different things?

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For the same reason you wouldn't want just one controller with 100 actions in it. If you only have one or two small things your site needs to use e-mail for, then one mailer would probably work fine. But if you have multiple e-mail-related components (for example, user registration/password management, newsletter subscriptions, notifications of events on the site, etc.) you may want to break those out into multiple mailers to help keep your code clean and structured.