Using SendGrid Incoming API with Python Flask

models.py

# Setup datastore model for storing mail
class ParsedMail(db.Model):
  from_address   = db.StringProperty()
  to_address     = db.StringProperty()
  text           = db.TextProperty()
  subject        = db.StringProperty()

urls.py

# Set up URL handler for the incoming mail
app.add_url_rule('/hook/parse-mail', view_func=views.parse_mail, methods=['POST'])

views.py

def parse_mail():
  envelope = simplejson.loads(request.form.get('envelope'))
  to_address = envelope['to'][0]
  from_address = envelope['from']
  text = request.form.get('text')
  subject = request.form.get('subject')

  # Save to datastore
  parsed_mail = ParsedMail(to_address=to_address, from_address=from_address, subject=subject, text=text)
  parsed_mail.save()

  # Reading attachments into a list
  attachments = []
  num_attachments = int(request.form.get('attachments', 0))
  if num_attachments > 0:
    for num in range(1, (num_attachments + 1)):
      attachment = request.files.get(('attachment%d' % num))
      attachments.append(attachment.read())

  # Do stuff with attachments and mail. Your call.