getmail --idle INBOX

[retriever]
type = SimpleIMAPSSLRetriever
server = secureimap.t-online.de
port = 993
username = <username>
password = <password>
mailboxes = ALL

[destination]
type = MDA_external
path = /usr/bin/procmail

[options]
# retrieve only new emails
read_all = false

:0 Wc:
| /usr/bin/python3 mail_handler.py

import sys
import email

full_msg = sys.stdin.read()
msg = email.message_from_string(full_msg)

author = msg['from']
to = msg['to']
subject = msg['subject']
body = msg['body']
date = msg['Date']

fname = '{}.txt'.format(date)
with open(fname, 'w') as f:
    f.write(full_msg)