contact.html

<p>
<a href="https://markjenkins.ca">Return to markjenkins.ca</a>
</p>

<p>
This contact form submits to my
<a href="mailto:mark@markjenkins.ca">mark@markjenkins.ca</a> email address.
</p>

<p>
I don't check it frequently.
</p>

<p>Please only use to submit text, unicode supported.
</p>

<p>
Include information on how to reach you if you need a reply.
</p>


<form action="/contactpost" method="POST" accept-charset="UTF-8">
<textarea name="msg" cols="80" rows="25"></textarea>
<div>
  <input type="submit" />
</div>
</form>

contactformtoemail.py

#!/usr/bin/env python3

# use only when developing
#import cgitb
#cgitb.enable()

import cgi
import html
from smtplib import (
    SMTP,
    SMTPRecipientsRefused,
    SMTPHeloError,
    SMTPSenderRefused,
    SMTPDataError,
    )

from email.message import Message
from email.utils import make_msgid
from hashlib import sha256
from email.utils import formatdate as RFC2822_currentdate

CONTACT_FORM_EMAIL = "contact@markjenkins.ca"
CONTACT_FORM_DEST_EMAIL = "mark@markjenkins.ca"
CONTACT_FORM_SUBJECT = "markjenkins.ca contact form"
CONTACT_FORM_DEST_SERVER = 'mail.skull.space'
CONTACT_DOMAIN_MID = 'markjenkins.ca'

def email_fail():
    print("Email delivery failed")

def custom_msg_gid(msg):
    return make_msgid(
        idstring=sha256(msg.encode('UTF-8')).hexdigest()[0:16],
        domain=CONTACT_DOMAIN_MID)

def main():
    print("Content-type: text/html")
    print()
    fs = cgi.FieldStorage()
    
    msg = fs.getfirst("msg")
    if msg == None:
        print("<h1>no msg recieved</h1>")
        print()
        return

    email_msg = Message()
    email_msg.set_unixfrom(CONTACT_FORM_EMAIL)
    email_msg.add_header("From", CONTACT_FORM_EMAIL)
    email_msg.add_header("To", CONTACT_FORM_DEST_EMAIL)
    email_msg.add_header("Subject", CONTACT_FORM_SUBJECT)
    email_msg.add_header(
        "Message-ID", custom_msg_gid(msg) )
    email_msg.add_header("Date", RFC2822_currentdate() )

    try:
        msg.encode('ascii')
    except UnicodeEncodeError:
        email_msg.set_payload(msg, charset="UTF-8")
    else:
        email_msg.set_payload(msg, charset='ascii')

    with SMTP(CONTACT_FORM_DEST_SERVER) as s:
        s.ehlo("markjenkins.ca") # FIXME, should be in a variable at the top
        try:
            s_result = s.send_message(
                email_msg,
                from_addr=CONTACT_FORM_EMAIL,
                to_addrs=[CONTACT_FORM_DEST_EMAIL])
        except (SMTPRecipientsRefused,
                SMTPHeloError,
                SMTPSenderRefused,
                SMTPDataError):
            email_fail()
        else:
            if len(s_result) == 0:
                print("<h1>Email sent</h1>")
                # FIXME, should be in a variable at the top for customization
                print('<a href="https://markjenkins.ca/">markjenkins.ca</a>')
            else:
                email_fail()
        print()

if __name__ == '__main__':
    main()