PySimpleGUI/DemoPrograms/Demo_Email_Send.py

import PySimpleGUI as sg

'''
    Learn how to send emails from PySimpleGUI using the smtplib and email modules
    
    The GUI portion is simple

    Based on a send-email script originally written by by Israel Dryer
    (Thank you Israel for figuring out the hard part of the stmp and email module calls!)
    
    Copyright 2019, 2022 PySimpleGUI

'''

# If you are using a mail service that's not gmail, hotmail, live or yahoo:
# then you can enter the smtp server address here so you don't have to keep typing it into the GUI
smtp_host_default = ''

# used for sending the email
import smtplib  as smtp
# used to build the email
from email.message import EmailMessage

# create and send email
def send_an_email(from_address, to_address, subject, message_text, user, password, smtp_host, smtp_port):
    server = smtp.SMTP(host=smtp_host, port=smtp_port)
    server.starttls()
    try:
        server.login(user=user, password=password)
    except Exception as e:
        sg.popup_error('Error authenticaing your email credentials', e, image=sg.EMOJI_BASE64_WEARY)
        server.close()
        return

    # create the email message headers and set the payload
    msg = EmailMessage()
    msg['From'] = from_address
    msg['To'] = to_address
    msg['Subject'] = subject
    msg.set_payload(message_text)

    # open the email server and send the message
    try:
        server.send_message(msg)
    except Exception as e:
        sg.popup_error('Error sending your email', e, image=sg.EMOJI_BASE64_WEARY)
        server.close()
        return

    server.close()
    sg.popup('Email sent successfully!', image=sg.EMOJI_BASE64_HAPPY_JOY)

'''
    important notes about using gmail

    - Gmail has locked things down pretty good with what it considers less secure apps. That 
        would include access your Gmail account from the smtplib library in Python. However, there 
        is a work around. You can enable access from "Less Secure Apps" by going to your Gmail 
        account and enabling that feature. However, you should do this at your own peril, and after 
        carefully reading the warnings: https://support.google.com/accounts/answer/6010255.

    smtplib | https://docs.python.org/3/library/smtplib.html?#module-smtplib   
    email.message | https://docs.python.org/3/library/email.message.html?#module-email.message   
    email examples in Python | https://docs.python.org/3.7/library/email.examples.html  
'''

def main():
    smtp_server_dict = {'gmail.com':'smtp.gmail.com','hotmail.com':'smtp.office365.com', 'live.com': 'smtp.office365.com', 'yahoo.com':'smtp.mail.yahoo.com'}

    sg.theme('Dark Blue 3')
    layout = [[sg.Text('Send an Email', font='Default 18')],
              [sg.T('From:', size=(8,1)), sg.Input(key='-EMAIL FROM-', size=(35,1))],
              [sg.T('To:', size=(8,1)), sg.Input(key='-EMAIL TO-', size=(35,1))],
              [sg.T('Subject:', size=(8,1)), sg.Input(key='-EMAIL SUBJECT-', size=(35,1))],
              [sg.T('Mail login information', font='Default 18')],
              [sg.T('User:', size=(8,1)), sg.Input(key='-USER-', size=(35,1), enable_events=True)],
              [sg.T('Password:', size=(8,1)), sg.Input(password_char='*', key='-PASSWORD-', size=(35,1))],
              [sg.T('SMTP Server Info', font='_ 14')],
              [sg.T('SMTP Hostname'), sg.Input(smtp_host_default, s=20, key='-SMTP HOST-'), sg.T('SMTP Port'), sg.In(587, s=4, key='-SMTP PORT-') ],
              [sg.Multiline('Type your message here', size=(60,10), key='-EMAIL TEXT-')],
              [sg.Button('Send'), sg.Button('Exit')]]

    window = sg.Window('Send An Email', layout)

    while True:
        event, values = window.read()
        if event in (sg.WIN_CLOSED, 'Exit'):
            break
        if event == 'Send':
            if values['-SMTP HOST-']:
                sg.popup_quick_message('Sending your message... this will take a moment...', background_color='red')
                send_an_email(from_address=values['-EMAIL FROM-'],
                              to_address=values['-EMAIL TO-'],
                              subject=values['-EMAIL SUBJECT-'],
                              message_text=values['-EMAIL TEXT-'],
                              user=values['-USER-'],
                              password=values['-PASSWORD-'],
                              smtp_host=values['-SMTP HOST-'],
                              smtp_port = values['-SMTP PORT-'])
            else:
                sg.popup_error('Missing SMTP Hostname... you have to supply a hostname (gmail, hotmail, live, yahoo are autofilled)')
        elif event == '-USER-':     # as the email sender is typed in, try to fill in the smtp hostname automatically
            for service in smtp_server_dict.keys():
                if service in values[event].lower():
                    window['-SMTP HOST-'].update(smtp_server_dict[service])
                    break

    window.close()

if __name__ == '__main__':
    main()