How do I send an email from Python?

POST JSON to https://sendandretain.com/api/v1/emails with your aem_ key as a Bearer token. requests or httpx is enough, and the call returns 202 with a message ID.

Is there a Python SDK for Send & Retain?

Not yet, and you don't need one. Any HTTP client works, and the example here uses plain requests so you can see the exact request.

Does it work with async Python?

Yes. Use an async client such as httpx inside FastAPI or any async service. The request, errors, and returned message ID are the same as the sync path.

How do I stop a retry from sending the same email twice?

Send an Idempotency-Key header that stays the same for one logical email, such as welcome plus the user ID. A retry with that key won't send a second email.

Can I send marketing emails from Python?

Yes, through automations. Send product events from Python, and automations you've turned on send the welcome, trial, or win-back emails. There are no newsletter blasts; every email goes to one person.

Send emails from Python

Transactional and marketing email from any Python service. One HTTP call with requests or httpx, and a message ID you can follow to the inbox.

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Server quickstart

Python

One request, complete trace

Request

POST /api/v1/emails

Authorization: Bearer aem_…

Idempotency-Key: welcome-8f21

{ "to": "[email protected]", "template": "welcome" }

202 Accepted

{ "id": "msg_7ca31", "status": "queued" }

RuntimeServer process

RequestPOST /api/v1/emails

Result202 · queued

Credentials stay server-sideInspect

[ 01 / 04 ]Quickstart

How do I send email from Python?

Three steps from no account to a queued email. No SDK needed.

Create an API key
In the dashboard, open Settings → API & MCP and create a key with the Send + manage permission (the default). It starts with aem_ and is shown once.
2
Store it as an environment variable
Keep the key on your server, never in client code. Your code reads it from AEM_KEY.
Terminal
export AEM_KEY="aem_..."

Send the email

POST the recipient and a published template. A retry with the same Idempotency-Key won't send a second email.

send_welcome.py

import os
import requests

response = requests.post(
    "https://sendandretain.com/api/v1/emails",
    headers={"Authorization": f"Bearer {os.environ['AEM_KEY']}",
             "Idempotency-Key": f"welcome-{user.id}"},
    json={"to": user.email, "template": "welcome"}, timeout=10,
)
response.raise_for_status()

4
Keep the message ID
A 202 means queued, not delivered. Store the id; delivery, bounce, and complaint events arrive later on your signed webhook.
202 Accepted
{ "id": "msg_7ca31", "status": "queued" }

[ 02 / 04 ]In production

What does a production Python integration need?

One shared HTTP client

Reuse a requests Session, or an httpx async client inside FastAPI and other async apps.

Retries with the same key

Retry timeouts and 5xx errors with the same Idempotency-Key, from Celery, RQ, or your own worker. Don't retry validation or auth errors.

Webhooks checked on the raw body

Verify the signature on the raw request body before your framework parses the JSON.

Events for marketing email

Send product events like signup or trial started. Automations you've turned on decide which email goes out.

[ 03 / 04 ]Example prompts

What can you ask your coding agent to do in Python?

Paste these into Claude Code, Cursor, or Codex. Connect the MCP server and it can build the templates and automations too.

Welcome email
“Find where we create users and send a welcome email with the Send & Retain API. Read the key from AEM_KEY and use the user ID as the idempotency key.”
Retries
“Move our email sends into a Celery task that retries timeouts and 5xx errors with the same Idempotency-Key, and never retries 4xx errors.”
Webhooks
“Add a FastAPI endpoint that verifies Send & Retain webhook signatures on the raw body and flags bounced addresses in our users table.”
Trial automation
“Send a trial_started event to Send & Retain when a trial begins, then build a paused trial automation for it.”

[ 04 / 04 ]Related

Questions people ask us

Everything else is in the docs.

Send your first email from Python.

Create a key, make one call, and follow the message ID to the inbox.

Start for free Read the API reference

Send emails from Python

How do I send email from Python?

Create an API key

Store it as an environment variable

Send the email

Keep the message ID

What does a production Python integration need?

One shared HTTP client

Retries with the same key

Webhooks checked on the raw body

Events for marketing email

What can you ask your coding agent to do in Python?

More ways to send email from Python

Django

FastAPI

Email API

Transactional email

Questions people ask us

Send your first email from Python.