# File lib/action_mailer/vendor/tmail-1.1.0/tmail/utils.rb, line 258
    def quote_boundary
      # Make sure the Content-Type boundary= parameter is quoted if it contains illegal characters
      # (to ensure any special characters in the boundary text are escaped from the parser
      # (such as = in MS Outlook's boundary text))
      if @body =~ /^(.*)boundary=(.*)$/m
        preamble = $1
        remainder = $2
        if remainder =~ /;/
          remainder =~ /^(.*)(;.*)$/m
          boundary_text = $1
          post = $2.chomp
        else
          boundary_text = remainder.chomp
        end
        if boundary_text =~ /[\/\?\=]/
          boundary_text = "\"#{boundary_text}\"" unless boundary_text =~ /^".*?"$/
          @body = "#{preamble}boundary=#{boundary_text}#{post}"
        end
      end
    end