…can actually use this lib with that Rails.
…or 1.8.7 compatibility
code that does not include active_support
/Users/doktahworm/.rvm/gems/ruby-1.8.7-p174/gems/mail-2.3.0/lib/mail/multibyte/chars.rb:342: warning: parenthesize argument(s) for future version /Users/doktahworm/.rvm/gems/ruby-1.8.7-p174/gems/mail-2.3.0/lib/mail/multibyte/chars.rb:350: warning: parenthesize argument(s) for future version
Hopefully it's pretty obvious that you need to require Mail for it to work. It even says so in the top of the README