Download all emails from Exchange/Office365 to an mbox file

maildump365.py

#!/usr/bin/env python3

import mailbox
import os
import sys
import traceback

from exchangelib import Account, Configuration, Credentials, DELEGATE


USERNAME = ''
PASSWORD = ''
SERVER = 'outlook.office365.com'

ID_FILE = '.read_ids'


def create_mailbox_message(e_msg):
    m = mailbox.mboxMessage(e_msg.mime_content)
    if e_msg.is_read:
        m.set_flags('S')
    return m

def get_read_ids():
    if os.path.exists(ID_FILE):
        with open(ID_FILE, 'r') as f:
            return set([s for s in f.read().splitlines() if s])
    else:
        return set()

def set_read_ids(ids):
    with open(ID_FILE, 'w') as f:
        for i in ids:
            if i:
                f.write(i)
                f.write(os.linesep)
    

if __name__ == '__main__':
    if len(sys.argv) != 3:
        print("Usage: {} folder_name mbox_file".format(sys.argv[0]))
        sys.exit()
    credentials = Credentials(USERNAME, PASSWORD)
    config = Configuration(server=SERVER, credentials=credentials)
    account = Account(primary_smtp_address=USERNAME, config=config, autodiscover=False, access_type=DELEGATE)
    mbox = mailbox.mbox(sys.argv[2])
    mbox.lock()
    read_ids_local = get_read_ids()
    folder = getattr(account, sys.argv[1], None)
    item_ids_remote = list(folder.all().order_by('-datetime_received').values_list('item_id', 'changekey'))
    total_items_remote = len(item_ids_remote)
    new_ids = [x for x in item_ids_remote if x[0] not in read_ids_local]
    read_ids = set()
    print("Total items in folder {}: {}".format(sys.argv[1], total_items_remote))
    for i, item in enumerate(account.fetch(new_ids), 1):
        try:
            msg = create_mailbox_message(item)
            mbox.add(msg)
            mbox.flush()
        except Exception as e:
            traceback.print_exc()
            print("[ERROR] {} {}".format(item.datetime_received, item.subject))
        else:
            if item.item_id:
                read_ids.add(item.item_id)
            print("[{}/{}] {} {}".format(i, len(new_ids), str(item.datetime_received), item.subject))
    mbox.unlock()
    set_read_ids(read_ids_local | read_ids)

sort_mbox.py

#!/usr/bin/env python3
# adapted from https://stackoverflow.com/a/368067/1027246

from datetime import datetime
from email.utils import parsedate
import mailbox
import sys
import time


def extract_date(email):
    date = email.get('Date')
    pd = parsedate(date)
    if pd:
        return time.mktime(pd)
    else:
        return time.time()


if __name__ == '__main__':
    mbox = mailbox.mbox(sys.argv[1])
    sorted_mails = sorted(mbox, key=extract_date)
    mbox.update(enumerate(sorted_mails))
    mbox.flush()