Welcome to the GNU Mailman shell

>>> import os
>>> import pickle
>>> for root, dirs, files in os.walk('/var/lib/mailman3/messages'):
...     for fn in files:
...         print(fn)
...         with open(os.path.join(root, fn), 'rb') as fp:
...             msg = pickle.load(fp)
...             print(msg['Message-ID'])
...             x = msg.as_string()
...
Q5PQZI4QEE4C42XNZMXESSKDCSZBUT4T
<1BFDD85F.4335D1D5@gmail.com>
Traceback (most recent call last):
  File "<console>", line 7, in <module>
  File "/usr/lib/python3.6/email/message.py", line 158, in as_string
    g.flatten(self, unixfrom=unixfrom)
  File "/usr/lib/python3.6/email/generator.py", line 116, in flatten
    self._write(msg)
  File "/usr/lib/python3.6/email/generator.py", line 181, in _write
    self._dispatch(msg)
  File "/usr/lib/python3.6/email/generator.py", line 214, in _dispatch
    meth(msg)
  File "/usr/lib/python3.6/email/generator.py", line 243, in _handle_text
    msg.set_payload(payload, charset)
  File "/usr/lib/python3.6/email/message.py", line 315, in set_payload
    payload = payload.encode(charset.output_charset)
UnicodeEncodeError: 'ascii' codec can't encode character '\ufffd' in position 467: ordinal not in range(128)
>>>