search_criterion = '(SENTSINCE 25-Nov-2010)'
            
gm = imaplib.IMAP4_SSL('imap.gmail.com', 993)
gm.login( bytes('mylogin@gmail.com', 'ASCII'), bytes('mypassword', 'ASCII') )
status, count = gm.select('Inbox', imaplib.IMAP4_SSL.readonly)

typ, data = gm.search(None, search_criterion)
messages = data[0].split()
message_count = len(messages)for k in range(first ,message_count) :
# list the last email found
typ, message_parts = gm.fetch(messages[len(messages)-1], 'RFC822')
message_body = str( message_parts[0][1] )
msg = email.message_from_string( message_body )
print(msg)
for part in msg.walk():
print(part.get_payload())

...
Mime-Version: 1.0
Content-Type: multipart/alternative; 
tboundary="----=_Part_22273_1831234854.1290718992094"
urn:schemas:mailheader:content-type: multipart/mixed

------=_Part_22273_1831234854.1290718992094
Content-Type: text/plain; charset=Windows-1251
Content-Transfer-Encoding: binary

\xd3\xe2\xe0\xe6\xe0\xe5\xec\xfb\xe9 \xea\xeb\xe8\xe5\xed\xf2...

>>> s = "\xd3\xe2\xe0\xe6\xe0\xe5\xec\xfb\xe9 \xea\xeb\xe8\xe5\xed\xf2"
>>> import feedparser
>>> feedparser.parse(s)
{'feed': {}, 'encoding': 'MacCyrillic', 'bozo': 1, 'version': '', 'namespaces': {}, 'entries': [], 'bozo_exception': SAXParseException('Document is empty\n',)}
>>> s.decode('MacCyrillic')
u'\u201d\u0432\u0430\u0436\u0430\u0435\u043c\u044b\u0439 \u043a\u043b\u0438\u0435\u043d\u0442'
>>> print s.decode('MacCyrillic')
”важаемый клиент
>>>

>>> b = b"\xd3\xe2\xe0\xe6\xe0\xe5\xec\xfb\xe9 \xea\xeb\xe8\xe5\xed\xf2"
>>> s = b.decode('cp1251')
>>> s
'Уважаемый клиент'
>>>

>>> s = "\xd3\xe2\xe0\xe6\xe0\xe5\xec\xfb\xe9 \xea\xeb\xe8\xe5\xed\xf2"
>>> s
'Óâàæàåìûé êëèåíò'
>>> d = {'Ó': 'У', 'â': 'в', 'à': 'а', 'æ': 'ж', 'å': 'е', 'ì': 'м', 'û': 'ы', 'é': 'й', 'ê': 'к', 'ë': 'л', 'è': 'и', 'í': 'н', 'ò': 'т' }
>>> s.translate(str.maketrans(d))
'Уважаемый клиент'
>>>

msg = email.message_from_string(str(b"\n".join(lines), "ascii", "ignore"))

typ, message_parts = gm.fetch(messages[k], 'RFC822')
message_body = str( message_parts[0][1] )