Good news: you're right... you don't need to pull down the RFC822. The message_parts
parameter to fetch()
lets you be quite fine-grained.
Here's a simple example of how to fetch just the header:
import imaplib
from email.parser import HeaderParser
conn = imaplib.IMAP4('my.host.com')
conn.login('[email protected]', 'mypassword')
conn.select()
conn.search(None, 'ALL') # returns a nice list of messages...
# let's say I pick #1 from this
data = conn.fetch(1, '(BODY[HEADER])')
# gloss over data structure of return... I assume you know these
# gives something like:
# ('OK', [(1 (BODY[HEADER] {1662', 'Received: etc....')])
header_data = data[1][0][1]
parser = HeaderParser()
msg = parser.parsestr(header_data)
<email.message.Message instance at 0x2a>
print msg.keys()
['Received', 'Received', 'Received', 'Cc', 'Message-Id', 'From', 'To',
'In-Reply-To', 'Content-Type', 'Content-Transfer-Encoding', 'Mime-Version',
'Subject', 'Date', 'References', 'X-Mailer',
'X-yoursite-MailScanner-Information',
'X-yoursite-MailScanner', 'X-yoursite-MailScanner-From', 'Return-Path',
'X-OriginalArrivalTime']
The full list of message parts that can be passed as the second argument to fetch
is in the IMAP4 spec: http://tools.ietf.org/html/rfc1730#section-6.4.5