Hi!

Your library keeps getting cooler, the send() thing is especially
interesting...

I just wanted to add a note about
naming_conventions() vs. namingConventions(). You could add

def method_missing(sym, *args, &block)
  parts = sym.to_s.split("_"); throw NameError(sym) if parts.size < 2
  camel_case = parts[0]+(parts[1..-1].map(){|x| x.capitalize }).join()
  send(camel_case, *args, &block)
end

to the Gmailer class, and omit all aliases - it will autoforward
messages named with _ to camelCased ones.
(not sure if it is the RubyWay, though : )