import imaplib
import email
import re

def get_message_count(connection):
    _, n = connection.select("INBOX")
    return int(n[0])

def extract_email(from_header):
    for match in re.findall(r"<(.+)>", str(message["from"])):
        return match
    return None

def delete_first_message(connection):
    connection.store("1", "+FLAGS", r"(\Deleted)")
    connection.expunge()

if __name__ == '__main__':
    connection = imaplib.IMAP4_SSL("imap.poczta.onet.pl")
    connection.login("janko.muzykant666@onet.pl", "abcdeF1@")
    while get_message_count(connection) > 0:
        _, data = connection.fetch("1", "(RFC822)")
        for response in data:
            if isinstance(response, tuple):
                message = email.message_from_bytes(response[1])
                from_email = extract_email(message["from"])
                delete_first_message(connection)
    connection.logout()