parse emails from files and separate the key components

parse.py

import os, re, email, sqlite3

conn = sqlite3.connect('mails.db')
c = conn.cursor()

c.execute('''CREATE TABLE emails
        (date text, frm text, recipient text, subject text, body text)''')

def cleanup(message):
    clean_html = (re.sub('<[^<]+?>', '', data)).replace('&nbsp;', ' ');
    return clean_html

def writedata(mail, body, table):
    date = mail.get('Date')
    frm = mail.get('From')
    to = mail.get('In-Reply-To')
    subject = mail.get('Subject')

    table.execute('INSERT INTO emails VALUES (?,?,?,?,?)', (date, frm, to, subject, body))
    conn.commit()

with open('out.csv', 'w') as csvfile:
    for filename in os.listdir():
        if filename.endswith("txt"):
            with open(filename, 'r', encoding="ISO-8859-1") as f:
                content = f.read()
                msgs = content.split('=========================================================================')

                for m in msgs:
                    mail = email.message_from_string(m.strip())
                    if mail.is_multipart():
                        for part in mail.walk():
                            body = part.get_payload(decode=True)
                            if body is not None:
                                data = body.decode("ISO-8859-1")
                                data = cleanup(data)
                                writedata(mail, data, c)
                    else:
                        body = mail.get_payload(decode=True)
                        data = body.decode("ISO-8859-1")
                        data = cleanup(data)
                        writedata(mail, data, c)
        else:
            continue
conn.close()