pyramid_mailer traceback

gistfile1.txt

Traceback (most recent call last):
  File "/Users/jim/uniregistrar/uniregistrar/uniregistrar/lib/tasks/job_task.py", line 79, in execute_job_task
    response = task_method(job_task)
  File "/Users/jim/uniregistrar/uniregistrar/uniregistrar/lib/tasks/file_upload_email_forward_task.py", line 29, in task_file_upload_email_forward
    result = file_upload_email_forward(user_id, account_id, job_data)
  File "/Users/jim/.virtualenv/unireg/lib/python2.7/site-packages/celery-3.1.8-py2.7.egg/celery/local.py", line 167, in <lambda>
    __call__ = lambda x, *a, **kw: x._get_current_object()(*a, **kw)
  File "/Users/jim/.virtualenv/unireg/lib/python2.7/site-packages/celery-3.1.8-py2.7.egg/celery/app/trace.py", line 417, in __protected_call__
    return orig(self, *args, **kwargs)
  File "/Users/jim/.virtualenv/unireg/lib/python2.7/site-packages/celery-3.1.8-py2.7.egg/celery/app/task.py", line 419, in __call__
    return self.run(*args, **kwargs)
  File "/Users/jim/uniregistrar/uniregistrar/uniregistrar/lib/tasks/file_upload_email_forward_task.py", line 74, in file_upload_email_forward
    self.mailer.send(message, SentEmailType.file_upload_forward)
  File "/Users/jim/uniregistrar/uniregistrar/uniregistrar/lib/mailer.py", line 27, in send
    self.pyramid_mailer.send_immediately(message)
  File "/Users/jim/.virtualenv/unireg/lib/python2.7/site-packages/pyramid_mailer-0.13-py2.7.egg/pyramid_mailer/mailer.py", line 261, in send_immediately
    return self.smtp_mailer.send(*self._message_args(message))
  File "/Users/jim/.virtualenv/unireg/lib/python2.7/site-packages/pyramid_mailer-0.13-py2.7.egg/pyramid_mailer/mailer.py", line 283, in _message_args
    msg = message.to_message()
  File "/Users/jim/.virtualenv/unireg/lib/python2.7/site-packages/pyramid_mailer-0.13-py2.7.egg/pyramid_mailer/message.py", line 268, in to_message
    attachment_mailbase = attachment.to_mailbase()
  File "/Users/jim/.virtualenv/unireg/lib/python2.7/site-packages/pyramid_mailer-0.13-py2.7.egg/pyramid_mailer/message.py", line 133, in to_mailbase
    charset = best_charset(self.data)[0]
  File "/Users/jim/.virtualenv/unireg/lib/python2.7/site-packages/pyramid_mailer-0.13-py2.7.egg/pyramid_mailer/message.py", line 512, in best_charset
    text = text.decode('ascii')
UnicodeDecodeError: 'ascii' codec can't decode byte 0xc3 in position 3051: ordinal not in range(128)