class Mail::EnvelopeFromElement

def formatted_date_time

use of UTC precludes the need for a timezone indicator);
traditional UNIX 'ctime' output sans timezone (note that the
was originally received, conformant with the syntax of the
a timestamp indicating the UTC date and time when the message
RFC 4155: 
def formatted_date_time
  if date_time
    if date_time.respond_to?(:ctime)
      date_time.ctime
    else
      date_time.strftime '%a %b %e %T %Y'
    end
  end
end