Python script to download CSV file attachments from an IMAP mailbox

download_mailbox_csv_attachments.py

# Download all csv file attachments from an IMAP mailbox, save in working dir, delete email(s) afterwards.
# IMPORTANT: all emails are deleted, even the ones that do not have (csv) attachments.

# Usage: python3 download_mailbox_csv_attachments.py {imap_host} {username} {password}

import imaplib, email, os, sys, random

if len(sys.argv) != 4:
    print('Invalid number of arguments')
    exit(1)

host = sys.argv[1]
user = sys.argv[2]
pw = sys.argv[3]

imaplib.IMAP4.debug = imaplib.IMAP4_SSL.debug = 1
con = imaplib.IMAP4_SSL(host, 993)
con.login(user, pw)
con.select()

typ, data = con.search(None, '(ALL)')
for num in data[0].split():
    typ, data = con.fetch(num, '(RFC822)')
    try:
        msg = email.message_from_bytes(data[0][1])
    except:
        continue
    for part in msg.walk():
        if part.get_content_maintype() == 'multipart':
            continue
        if part.get('Content-Disposition') is None:
            continue
        filename = part.get_filename()
        if not filename.lower().endswith('.csv'):
            continue
        data = part.get_payload(decode=True)
        if not data:
            continue
        dest = '%d_%s' % (random.randint(0,10000), filename.lower())
        print(dest)
        f = open(dest, 'wb')
        f.write(data)
        f.close()
    con.store(num, '+FLAGS', '\\Deleted')
con.expunge()
con.close()
con.logout()