SMTP Tester

smtp_tester.py

# Code generated by Claude 3.5 Sonnet, an AI assistant created by Anthropic.
import smtplib
import ssl
from email.mime.text import MIMEText
from email.mime.multipart import MIMEMultipart
from typing import Optional


def test_smtp_connection(
    sendgrid_username: str,
    sendgrid_password: str,
    sender_email: str,
    recipient_email: str,
    subject: str = "SMTP Test",
    body: str = "This is a test email sent using SendGrid.",
) -> Optional[str]:
    """
    Test SMTP connection using SendGrid and send a test email.

    This function establishes a secure SSL connection to SendGrid's SMTP server,
    authenticates using the provided credentials, and sends a test email.

    Args:
        sendgrid_username (str): SendGrid username (typically "apikey").
        sendgrid_password (str): SendGrid API key.
        sender_email (str): Email address of the sender.
        recipient_email (str): Email address of the recipient.
        subject (str, optional): Subject of the test email. Defaults to "SMTP Test".
        body (str, optional): Body of the test email. Defaults to a generic test message.

    Returns:
        Optional[str]: None if the email was sent successfully, or an error message if it failed.

    Raises:
        smtplib.SMTPException: If there's an error during the SMTP operation.
        ssl.SSLError: If there's an SSL-related error.
    """
    smtp_server = "smtp.sendgrid.net"
    port = 465  # For SSL

    message = MIMEMultipart()
    message["From"] = sender_email
    message["To"] = recipient_email
    message["Subject"] = subject
    message.attach(MIMEText(body, "plain"))

    context = ssl.create_default_context()

    try:
        with smtplib.SMTP_SSL(smtp_server, port, context=context) as server:
            server.login(sendgrid_username, sendgrid_password)
            server.send_message(message)
        return None
    except (smtplib.SMTPException, ssl.SSLError) as e:
        return f"Failed to send email: {str(e)}"


if __name__ == "__main__":
    sendgrid_username = "apikey"  # This is typically "apikey" for SendGrid
    sendgrid_password = "SG.xxxxx"  # Replace with your actual SendGrid API key
    sender_email = "[email protected]"
    recipient_email = "[email protected]"

    result = test_smtp_connection(
        sendgrid_username, sendgrid_password, sender_email, recipient_email
    )
    if result is None:
        print("Email sent successfully")
    else:
        print(result)