Bab 18: Email & SMS¶

Notifikasi otomatis = produktivitas tanpa harus jadi babysitter aplikasi.

Setelah Bab 18, kamu akan bisa:

Kirim email otomatis dengan SMTP
Baca email dari inbox dengan IMAP
Kirim SMS dengan Twilio
Project: notifikasi error otomatis

18.1. Kirim Email dengan SMTP¶

flowchart LR
    Script["🐍 Python<br/>script"]
    SMTP["📡 SMTP Server<br/>(smtp.gmail.com:465)"]
    Inbox["📥 Inbox<br/>penerima"]

    Script -- "1. Login<br/>email + app password" --> SMTP
    Script -- "2. Kirim message<br/>(MIMEMultipart)" --> SMTP
    SMTP -- "3. Routing internet" --> Inbox

    style Script fill:#1a1a1a,stroke:#6366f1,color:#fafafa
    style SMTP fill:#1a1a1a,stroke:#f59e0b,color:#fafafa
    style Inbox fill:#1a1a1a,stroke:#10b981,color:#fafafa

Cara baca diagram

Diagram ini menunjukkan 3 pihak yang terlibat saat kirim email dari Python.

Script (indigo) = kode Python kamu. Tidak punya kemampuan kirim email langsung — dia delegasikan ke SMTP server.
SMTP server (amber) = "kantor pos" digital. Untuk Gmail, alamatnya smtp.gmail.com di port 465 (SSL).
Inbox penerima (hijau) = tujuan akhir. Bisa Gmail, Yahoo, kantor, dll.

Alur kirim email:

Login — script connect ke SMTP server, autentikasi dengan email + App Password (bukan password Google biasa).
Kirim message — script siapkan email object (MIMEMultipart), submit ke server.
Routing — server forward ke alamat penerima via internet.

Kenapa butuh App Password (bukan password biasa)? Google block "less secure apps" sejak 2022. App Password adalah token khusus untuk app yang tidak support OAuth — generate dari myaccount.google.com/apppasswords.

Untuk service lain: - Outlook: smtp-mail.outlook.com port 587 (TLS) - Yahoo: smtp.mail.yahoo.com port 465 (SSL) - Kantor (Office 365): smtp.office365.com port 587

Selalu cek dokumentasi provider email kamu untuk port & encryption yang tepat.

Setup Gmail¶

Untuk Gmail, kamu perlu App Password (bukan password Google biasa):

Aktifkan 2FA di akun Google
Pergi ke myaccount.google.com/apppasswords
Generate password 16 karakter, copy
Pakai password itu di script (bukan password login biasa)

Kirim Email Sederhana¶

import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart

def kirim_email(to, subject, body, from_email, from_password):
    msg = MIMEMultipart()
    msg["From"] = from_email
    msg["To"] = to
    msg["Subject"] = subject

    msg.attach(MIMEText(body, "plain"))

    # Connect ke Gmail SMTP
    with smtplib.SMTP_SSL("smtp.gmail.com", 465) as smtp:
        smtp.login(from_email, from_password)
        smtp.send_message(msg)

    print(f"✓ Email terkirim ke {to}")

kirim_email(
    to="penerima@example.com",
    subject="Test Email dari Python",
    body="Halo, ini email otomatis dari script Python!",
    from_email="kamu@gmail.com",
    from_password="abcd_efgh_ijkl_mnop",  # App Password
)

Email dengan HTML & Attachment¶

from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from email.mime.base import MIMEBase
from email import encoders
from pathlib import Path

def kirim_email_lengkap(to, subject, html_body, attachments=None):
    msg = MIMEMultipart()
    msg["From"] = FROM_EMAIL
    msg["To"] = to
    msg["Subject"] = subject

    msg.attach(MIMEText(html_body, "html"))

    if attachments:
        for path in attachments:
            path = Path(path)
            with open(path, "rb") as f:
                part = MIMEBase("application", "octet-stream")
                part.set_payload(f.read())
            encoders.encode_base64(part)
            part.add_header(
                "Content-Disposition",
                f'attachment; filename="{path.name}"',
            )
            msg.attach(part)

    with smtplib.SMTP_SSL("smtp.gmail.com", 465) as smtp:
        smtp.login(FROM_EMAIL, FROM_PASSWORD)
        smtp.send_message(msg)

html = """
<html>
  <body>
    <h1 style="color: #4f46e5;">Laporan Mingguan</h1>
    <p>Berikut <strong>laporan</strong> minggu ini.</p>
    <ul>
      <li>Pendapatan: Rp 50jt</li>
      <li>Pengeluaran: Rp 30jt</li>
    </ul>
  </body>
</html>
"""

kirim_email_lengkap(
    to="bos@kantor.com",
    subject="Laporan Mingguan",
    html_body=html,
    attachments=["laporan.pdf", "data.xlsx"],
)

18.2. Baca Email dengan IMAP¶

import imaplib
import email

def baca_email_terbaru(email_user, password, jumlah=5):
    with imaplib.IMAP4_SSL("imap.gmail.com") as mail:
        mail.login(email_user, password)
        mail.select("inbox")

        # Cari semua email
        status, msg_ids = mail.search(None, "ALL")
        ids = msg_ids[0].split()

        # Ambil N terakhir
        for msg_id in ids[-jumlah:]:
            status, data = mail.fetch(msg_id, "(RFC822)")
            msg = email.message_from_bytes(data[0][1])

            print(f"From: {msg['From']}")
            print(f"Subject: {msg['Subject']}")
            print(f"Date: {msg['Date']}")
            print("-" * 50)

baca_email_terbaru("kamu@gmail.com", "app_password")

18.3. SMS dengan Twilio¶

Twilio = service kirim SMS via API. Daftar gratis dengan trial credit.

pip install twilio

from twilio.rest import Client

ACCOUNT_SID = "ACxxxxxxxxxxxxxxxx"
AUTH_TOKEN = "yyyyyyyyyyyyyyyyyy"
TWILIO_NUMBER = "+15555551234"  # nomor Twilio kamu

def kirim_sms(to_number, pesan):
    client = Client(ACCOUNT_SID, AUTH_TOKEN)
    message = client.messages.create(
        body=pesan,
        from_=TWILIO_NUMBER,
        to=to_number,
    )
    print(f"✓ SMS terkirim. SID: {message.sid}")

kirim_sms("+6281234567890", "Halo dari Python!")

18.4. Project: Email Notification Saat Error¶

import smtplib
import traceback
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart

ADMIN_EMAIL = "admin@kantor.com"

def kirim_error_email(error_msg, traceback_text):
    msg = MIMEMultipart()
    msg["From"] = "alert@kantor.com"
    msg["To"] = ADMIN_EMAIL
    msg["Subject"] = "🚨 ERROR di script"

    body = f"""
    Script error pada {datetime.now()}:

    Error: {error_msg}

    Traceback:
    {traceback_text}
    """

    msg.attach(MIMEText(body, "plain"))

    with smtplib.SMTP_SSL("smtp.gmail.com", 465) as smtp:
        smtp.login(FROM_EMAIL, FROM_PASSWORD)
        smtp.send_message(msg)

def kerjaan_kritis():
    """Function yang harus jalan tiap hari."""
    # ... kode kerja kritis ...
    raise ValueError("Database connection failed")

try:
    kerjaan_kritis()
except Exception as e:
    kirim_error_email(str(e), traceback.format_exc())

Setiap kali script crash, kamu langsung dapat email dengan detail error.

18.5. Tips¶

Jangan hardcode credential

Jangan tulis password langsung di kode. Pakai environment variable atau file .env:

import os
FROM_EMAIL = os.getenv("EMAIL_USER")
FROM_PASSWORD = os.getenv("EMAIL_PASSWORD")

Atau pakai library python-dotenv:

pip install python-dotenv

from dotenv import load_dotenv
load_dotenv()  # baca .env file

Anti-Spam

Jangan kirim email massal tanpa consent. Banyak negara punya anti-spam law (SPAM Act, GDPR, dll). Pakai service email marketing resmi (SendGrid, Mailchimp) untuk legal compliance.

18.6. Ringkasan¶

smtplib untuk kirim email (gunakan SSL port 465)
App Password untuk Gmail (bukan password biasa)
MIMEMultipart untuk email kompleks (HTML + attachment)
imaplib untuk baca email
Twilio untuk SMS (atau alternatif: Vonage, MessageBird)
Jangan hardcode credential — pakai env variable

18.7. Latihan¶

18.1 — Birthday Reminder¶

Baca CSV berisi nama + tanggal lahir. Kirim email ke yang ulang tahun hari ini.

18.2 — Auto-Responder¶

Cek inbox, balas otomatis ke email dengan subject mengandung "out of office".

Kirim email newsletter ke list subscriber, isi diambil dari file template Markdown.

SMTP Server¶

Provider	Host	Port
Gmail	smtp.gmail.com	465 (SSL)
Outlook	smtp-mail.outlook.com	587 (TLS)
Yahoo	smtp.mail.yahoo.com	465 (SSL)
Office 365	smtp.office365.com	587 (TLS)

Gmail App Password¶

Aktifkan 2FA
myaccount.google.com/apppasswords
Pakai 16-char password (bukan password Google)

Kirim Email¶

import smtplib
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart

msg = MIMEMultipart()
msg["From"] = "from@gmail.com"
msg["To"] = "to@gmail.com"
msg["Subject"] = "Subject"

msg.attach(MIMEText(body, "plain"))   # atau "html"

with smtplib.SMTP_SSL("smtp.gmail.com", 465) as smtp:
    smtp.login(email, app_password)
    smtp.send_message(msg)

Attachment¶

from email.mime.base import MIMEBase
from email import encoders

with open(file_path, "rb") as f:
    part = MIMEBase("application", "octet-stream")
    part.set_payload(f.read())
encoders.encode_base64(part)
part.add_header(
    "Content-Disposition",
    f'attachment; filename="{filename}"',
)
msg.attach(part)

Baca Email (IMAP)¶

import imaplib
import email

with imaplib.IMAP4_SSL("imap.gmail.com") as mail:
    mail.login(user, password)
    mail.select("inbox")

    status, ids = mail.search(None, "ALL")
    for msg_id in ids[0].split()[-5:]:
        status, data = mail.fetch(msg_id, "(RFC822)")
        msg = email.message_from_bytes(data[0][1])
        print(msg["From"], msg["Subject"])

Twilio SMS¶

pip install twilio

from twilio.rest import Client

client = Client(account_sid, auth_token)
client.messages.create(
    body="pesan",
    from_=twilio_number,
    to="+62...",
)

Aman: Pakai Env Variable¶

import os
EMAIL = os.getenv("EMAIL_USER")
PASSWORD = os.getenv("EMAIL_PASSWORD")

# .env (jangan commit ke Git!)
EMAIL_USER=...
EMAIL_PASSWORD=...

← Bab 17 Lanjut Bab 19 →

Diadaptasi dari Chapter 18: Sending Email and Text Messages, "Automate the Boring Stuff with Python" karya Al Sweigart. Dilisensikan CC BY-NC-SA 4.0.