So I''ve finally committed Action Mailer to CVS: 
http://rubyforge.org/scm/?group_id=361
If you''re going to use it on your Rails installation, put it into 
vendor/ and add "vendor/actionmailer/lib" to ADDITIONAL_LOAD_PATHS in 
config/environments/shared.rb
If you don''t want to fool around with all that, you can also just wait 
for the next version of Rails. Action Mailer will be included in that.
--
David Heinemeier Hansson,
http://www.rubyonrails.org/  -- Web-application framework for Ruby
http://www.instiki.org/      -- A No-Step-Three Wiki in Ruby
http://macromates.com/       -- TextMate: Code and markup editor for OS 
X
http://www.basecamphq.com/   -- Web-based Project Management
http://www.loudthinking.com/ -- Broadcasting Brain
http://www.nextangle.com/    -- Development & Consulting Services