Mark all mail (and maildirs, recursively) as read within the given Maildir. Requires the 'maildir' gem.

markall.rb

#!/usr/bin/env ruby
require 'maildir'
 
class Maildir
  def subdirectories
        dirs = Dir.glob(File.join(@path,"*")).find_all{|a|File.directory?(a)}
        dirs.map{|a|Maildir.new(a)}
  end

  def read_all!
        self.list(:new).each{|l|l.process}
        self.list(:cur).each{|m|m.seen!}
  end
end

START_DIR="~/Maildir"

md = Maildir.new(START_DIR)
md.read_all!
md.subdirectories.each do |s|
  s.read_all!
end