old_contents: import hashlib
  
  GRAVATAR_URL_TEMPLATE = 'https://www.gravatar.com/avatar/{hash}?s={size}'
  
  def gravatar_url(email, size=80):
      hash = hashlib.md5(email.lower().encode()).hexdigest()
      return GRAVATAR_URL_TEMPLATE.format(hash=hash, size=size)
  
new_contents: import hashlib
  
  GRAVATAR_URL_TEMPLATE = ('https://secure.gravatar.com/avatar/{hash}'
                           '?s={size}&d=wavatar')
  
  def gravatar_url(email, size=80):
      hash = hashlib.md5(email.lower().encode()).hexdigest()
      return GRAVATAR_URL_TEMPLATE.format(hash=hash, size=size)
  
subject: tweak gravatars