Index of e-mail’s

Traceback (most recent call last):
  File "utils/mage3.py", line 108, in 
    msg = email.message_from_string(Imap_Fetch_Data)
  File "/usr/lib/python3.6/email/__init__.py", line 38, in message_from_string
    return Parser(*args, **kws).parsestr(s)
  File "/usr/lib/python3.6/email/parser.py", line 68, in parsestr
    return self.parse(StringIO(text), headersonly=headersonly)
TypeError: initial_value must be str or None, not list