Unitpost/Guides

Send email from FastAPI over SMTP

Call Python's SMTP client from a FastAPI route. Same host, username, and API-key password as every other stack.

What are the SMTP settings?

Hostsmtp.unitpost.com
Usernameunitpost(always this literal value)
PasswordYour Unitpost API key(must carry emails:send)
Port (STARTTLS)587(or 2587 if blocked)
Port (implicit TLS)465(or 2465 if blocked)
From addressAny address on a verified domain

How do I set it up?

  1. Send from a route

    Python
    import os
import smtplib
from email.message import EmailMessage
from fastapi import FastAPI

app = FastAPI()

@app.post("/send")
def send() -> dict[str, bool]:
    msg = EmailMessage()
    msg["From"] = "you@yourdomain.com"
    msg["To"] = "customer@example.com"
    msg["Subject"] = "Hello from FastAPI"
    msg.set_content("Sent via SMTP.")
    with smtplib.SMTP("smtp.unitpost.com", 587) as smtp:
        smtp.starttls()
        smtp.login("unitpost", os.environ["UNITPOST_API_KEY"])
        smtp.send_message(msg)
    return {"ok": True}

  2. Verify delivery

    Confirm in Activity.