Sending emails in gmail in an easy, python3 script

send-emails-using-gmail-api.py

# Modified from https://stackoverflow.com/a/37267330/2965993
# I cannot believe how freaking difficult it is to send an email in gmail... hopefully this will simplify it

import httplib2
import base64
from email.mime.multipart import MIMEMultipart
from email.mime.text import MIMEText
from apiclient import errors, discovery
from oauth2client import file, client, tools


SCOPES = 'https://www.googleapis.com/auth/gmail.send'
CLIENT_SECRET_FILE = 'client_id.json'
APPLICATION_NAME = 'Gmail API Python Send Email'


def get_credentials():
    store = file.Storage('credentials.json')
    flow = client.flow_from_clientsecrets(CLIENT_SECRET_FILE, SCOPES)
    flow.user_agent = APPLICATION_NAME
    return tools.run_flow(flow, store)


def create_message(sender, to, subject, body):
    msg = MIMEMultipart('alternative')
    msg['Subject'] = subject
    msg['From'] = sender
    msg['To'] = to
    msg.attach(MIMEText(body, 'html'))
    return {'raw': base64.urlsafe_b64encode(msg.as_bytes()).decode()}


def send_email(sender, to, subject, body):
    credentials = get_credentials()
    http = credentials.authorize(httplib2.Http())
    service = discovery.build('gmail', 'v1', http=http)
    message = create_message(sender, to, subject, body)
    try:
        message = (service.users().messages().send(userId="me", body=message).execute())
        return message
    except errors.HttpError as error:
        print('An error occurred: %s' % error)


if __name__ == '__main__':
    res = send_email(
        "receiver@gmail.com",
        "sender@gmail.com",
        "Subject matter",
        "Your body is a temple"
    )
    print(res)