#!/usr/bin/python
# fix_date.py - corrects the received date in IMAP folders.

# Description: 
#     When moving mail between IMAP servers, the received date can become 
#     reset to the date when the message was added to the new server. This 
#     script attempts to fix this by setting the received date to the date the
#     message was sent. 

# Usage: 
#     Set the 5 variables below to suit your setup, and then run the script. 
#     If you run the script with the argument '--list', then it will just list
#     all the mailboxes on the server. Useful if you don't know the exact name 
#     of the mailboxes.

# Notes: 
#     Due to the may IMAP works, you cannot change the recieved date for an 
#     existing message. To get round this, fix_date.py makes a new copy of the
#     message in a different folder. As it has to copy each message, process 
#     can take some time!
#     With some additional work the date could be set to the last received hop 
#     in the mail's delivery, but I didn't need that accuracy.


import imaplib
import email.Utils
import sys

# Change the following 5 lines as applicable:

source = "INBOX.Source" # The source folder to read the messages to fix.
dest   = "INBOX.Dest" # The destination folder to save to new copy. 
server = "imap.example.com" # IMAP server address
user   = "user" # Username     
passwd = "password" # Password


M = imaplib.IMAP4(server)
M.login(user, passwd)

if len(sys.argv) == 2 and sys.argv[1] == '--list':
	print "List of mailboxes available on server:"
	for mbox in M.list()[1]:
		print mbox.split('"."')[1]
else:
	M.select(source)

	typ, data = M.search(None, 'ALL')
	for num in data[0].split():
		typ, date = M.fetch(num, '(BODY[HEADER.FIELDS (DATE)])')
		typ, body = M.fetch(num, '(RFC822)')
		date_str = date[0][1][6:].strip()
		datetime = email.Utils.parsedate(date_str)
		print "Message (" + num + "), date:" + date_str
		M.append(dest, None, imaplib.Time2Internaldate(datetime), body[0][1]) 
		#print body[0][1]
	M.logout()