I'm trying to send emails of various sizes using the Gmail API and the functions below.

Generally this works perfectly, however for attachments over around 10MB (which are rare but will happen) I recieve `Errno 10053` which I *think* is because I timeout when sending the message including the large attachment. 

Is there a way around this by say, specifying size or increasing the timeout limit? There's reference to size in the Gmail API docs, but I'm struggling to understand how to use in Python or whether it would even help.

```
def CreateMessageWithAttachment(sender, to, cc, subject,
                                message_text, file_dir, filename):
  """Create a message for an email.

  Args:
    sender: Email address of the sender.
    to: Email address of the receiver.
    subject: The subject of the email message.
    message_text: The text of the email message.
    file_dir: The directory containing the file to be attached.
    filename: The name of the file to be attached.

  Returns:
    An object containing a base64url encoded email object.
  """
  message = MIMEMultipart()
  message['to'] = to
  if cc != None:
    message['cc'] = cc
  message['from'] = sender
  message['subject'] = subject

  msg = MIMEText(message_text)
  message.attach(msg)

  path = os.path.join(file_dir, filename)
  content_type, encoding = mimetypes.guess_type(path)

  QCoreApplication.processEvents()

  if content_type is None or encoding is not None:
    content_type = 'application/octet-stream'
  main_type, sub_type = content_type.split('/', 1)
  if main_type == 'text':
    fp = open(path, 'rb')
    msg = MIMEText(fp.read(), _subtype=sub_type)
    fp.close()
  elif main_type == 'image':
    fp = open(path, 'rb')
    msg = MIMEImage(fp.read(), _subtype=sub_type)
    fp.close()
  elif main_type == 'audio':
    fp = open(path, 'rb')
    msg = MIMEAudio(fp.read(), _subtype=sub_type)
    fp.close()
  else:
    fp = open(path, 'rb')
    msg = MIMEBase(main_type, sub_type)
    msg.set_payload(fp.read())
    fp.close()
  QCoreApplication.processEvents()

  msg.add_header('Content-Disposition', 'attachment', filename=filename)
  message.attach(msg)
  return {'raw': base64.urlsafe_b64encode(message.as_string())}

def SendMessage(service, user_id, message, size):
  """Send an email message.

  Args:
    service: Authorized Gmail API service instance.
    user_id: User's email address. The special value "me"
    can be used to indicate the authenticated user.
    message: Message to be sent.

  Returns:
    Sent Message.
  """

  try:
    message = (service.users().messages().send(userId=user_id, body=message)
               .execute())
    QCoreApplication.processEvents()
    return message
  except errors.HttpError, error:
    pass

```