Send email with SendGrid from Python (sendgrid-python v6)

TL;DR: The exact working pattern for sendgrid-python: env-based key, Mail helper builders, and how to read the 202 response. Includes the verified-sender gotcha that turns a good request into a 403. Install: pip install sendgrid. Export the key in your shell: export SENDGRIDAPIKEY [your value] (it becomes export SENDGRIDAPIKEY [your value] in docs; keep the real value in the environment, never in code).

The fix

1. Install: pip install sendgrid.
2. Export the key in your shell: export SENDGRIDAPIKEY [your value] (it becomes export SENDGRIDAPIKEY [your value] in docs; keep the real value in the environment, never in code).
3. Build the message with the helper classes: import sendgrid, os from sendgrid.helpers.mail import Mail, Email, To, Content sg = sendgrid.SendGridAPIClient(apikey value os.environ.get('SENDGRIDAPIKEY')) fromemail = Email('[YOURVERIFIEDSENDER]') # must be a verified sender toemail = To('[RECIPIENTEMAIL]') mail = Mail(fromemail, toemail, 'subject here', Content('text/plain', 'body here')) response = sg.client.mail.send.post(requestbody=mail.get()) print(response.statuscode) # 202 means accepted
4. The from address must be a verified sender (domain auth or single sender). An unverified from is the most common reason a correct request fails.
5. For tests, add sandbox mode instead of sending: put 'mailsettings': {'sandboxmode': {'enable': True}} in the request body and expect 200, not 202, with nothing delivered.
6. On failure, print response.body and response.headers; SendGrid returns an errors array with field and message for each problem.

When to use this

• This covers exactly what the title says: Send email with SendGrid from Python (sendgrid-python v6).
• You are setting this up for the first time, or auditing an existing setup.
• You want the key gotchas in one place before you start.

When not to use this

• You are doing a different workflow with Send; these steps are specific to the title above.
• You need the full reference docs; this is the short path, not the manual.

Compatibility

• Not pinned to a specific version; follows current Send behavior.

The official Python quickstart pins the exact working pattern: pip install sendgrid, SendGridAPIClient with the key from the environment, Mail/Email/To/Content helpers, and sg.client.mail.send.post. A successful request returns 202. Sources: https://github.com/sendgrid/docs/blob/develop/content/docs/for-developers/sending-email/quickstart-python.md | https://github.com/sendgrid/sendgrid-python | https://docs.sendgrid.com/api-reference/mail-send/mail-send