SendGrid Sandbox Mode — Testing Email Sending Without Delivery

from sendgrid import SendGridAPIClient
from sendgrid.helpers.mail import Mail, SandBoxMode, MailSettings
import base64

def send_test_email_sandbox(to_email, template_id, template_data):
    sg = SendGridAPIClient(SENDGRID_API_KEY)

    message = Mail(
        from_email='test@dodatech.com',
        to_emails=to_email,
        subject='[TEST] Welcome Email'
    )
    message.template_id = template_id
    message.dynamic_template_data = template_data

    # Enable sandbox mode
    mail_settings = MailSettings()
    mail_settings.sandbox_mode = SandBoxMode(enable=True)
    message.mail_settings = mail_settings

    try:
        response = sg.send(message)
        # Sandbox returns 200 OK with no email actually sent
        print(f"Test passed! Status: {response.status_code}")
        print("No email was delivered.")
        return True
    except Exception as e:
        print(f"Test failed: {str(e)}")
        return False

def test_attachment_format():
    """Test that attachments are properly formatted without sending"""
    pdf_content = b'%PDF-1.4 test content for validation'
    pdf_encoded = base64.b64encode(pdf_content).decode()

    message = Mail(
        from_email='test@dodatech.com',
        to_emails='test@example.com',
        subject='Test Attachment',
        html_content='<p>Test attachment</p>'
    )

    # Add test attachment
    from sendgrid.helpers.mail import Attachment, FileContent, FileName, FileType, Disposition
    attachment = Attachment(
        FileContent(pdf_encoded),
        FileName('test.pdf'),
        FileType('application/pdf'),
        Disposition('attachment')
    )
    message.add_attachment(attachment)

    # Enable sandbox
    mail_settings = MailSettings()
    mail_settings.sandbox_mode = SandBoxMode(enable=True)
    message.mail_settings = mail_settings

    sg = SendGridAPIClient(SENDGRID_API_KEY)
    response = sg.send(message)

    # Verify response
    assert response.status_code == 200 or response.status_code == 202
    print("Attachment test passed!")

    # Validate attachment size
    assert len(pdf_encoded) < 100000  # Max size check
    print(f"Attachment size: {len(pdf_encoded)} bytes (encoded)")

import requests

def test_email_via_api_sandbox():
    """Test email request formatting via raw API with sandbox"""
    response = requests.post(
        "https://api.sendgrid.com/v3/mail/send",
        headers={
            "Authorization": f"Bearer {SENDGRID_API_KEY}",
            "Content-Type": "application/json"
        },
        json={
            "personalizations": [{
                "to": [{"email": "test@example.com"}],
                "dynamic_template_data": {
                    "userName": "Test User",
                    "companyName": "DodaTech"
                }
            }],
            "from": {"email": "test@dodatech.com"},
            "subject": "[TEST] Welcome",
            "content": [{"type": "text/html", "value": "<p>Test</p>"}],
            "mail_settings": {
                "sandbox_mode": {
                    "enable": True
                }
            }
        }
    )

    if response.status_code == 202:
        print("API test passed! Sandbox mode prevented delivery.")
        return True
    else:
        print(f"API test failed: {response.status_code} {response.text}")
        return False