# SMTP submission Send from a system that only speaks SMTP, with the same key and rules. Use SMTP when a system cannot call an HTTP API, such as an ERP or a printer. A message sent over SMTP goes through the same checks as an API send. It appears in the same log, gets the same events and counts against the same limits. ## Connect | Setting | Value | | ---------------------- | ---------------------------------------------------------------------------------- | | Host | `smtp.sendora.se` | | Port | 465 with TLS from the start, or 587 with STARTTLS | | User name and password | A server key, `sk_…` or a [test server](https://sendora.se/docs/test-servers)'s `sk_test_…`, as both | | Authentication | `PLAIN` or `LOGIN`, once TLS is on | The `From` address must be on one of the server's verified domains. The [message limits](https://sendora.se/docs/limits#messages) apply as they do over the API, with `To`, `Cc` and `Bcc` counted together. TypeScript: ```ts import nodemailer from 'nodemailer'; /** Sends one message over SMTP with a server's API token as both user name and password. */ export async function sendOverSmtp( token: string, ): Promise { const transport = nodemailer.createTransport({ host: 'smtp.sendora.se', port: 587, secure: false, requireTLS: true, auth: { user: token, pass: token }, }); const info = await transport.sendMail({ from: '"Example AB" ', to: 'anna@example.com', subject: 'Your account is ready', text: 'Hi Anna, your account at Example is ready.', headers: { 'X-Sendora-Tag': 'welcome', 'X-Sendora-Metadata-Customer': '4711', }, }); return info.response; // "250 2.0.0 OK: queued as " } ``` Python: ```python import smtplib import ssl from email.message import EmailMessage # Sends one message over SMTP with a server's API # token as both user name and password. def send_over_smtp(token: str) -> None: message = EmailMessage() message["From"] = "Example AB " message["To"] = "anna@example.com" message["Subject"] = "Your account is ready" message["X-Sendora-Tag"] = "welcome" message["X-Sendora-Metadata-Customer"] = "4711" message.set_content( "Hi Anna, your account at Example is ready." ) # Without a context of its own, starttls() would # accept any certificate, and without a timeout # smtplib waits forever on a stalled connection. context = ssl.create_default_context() with smtplib.SMTP( "smtp.sendora.se", 587, timeout=30 ) as smtp: smtp.starttls(context=context) smtp.login(token, token) smtp.send_message(message) ``` Sendora delivers only to the envelope recipients, the addresses your client gives in `RCPT TO`. The `To` and `Cc` headers decide how each of them is shown, and an envelope recipient that neither header names is sent as Bcc. An address that only a header names gets nothing. ## Send from Django Django sends over SMTP out of the box and checks the server's certificate when it starts TLS. In `settings.py`, use the server key from the environment as both user name and password. `DEFAULT_FROM_EMAIL` must be on a verified domain, and so must `SERVER_EMAIL`, the address Django sends its error mail from. ```python import os # In settings.py, for Django's SMTP backend, its # default: the server key as user name and password. EMAIL_HOST = "smtp.sendora.se" EMAIL_PORT = 587 EMAIL_USE_TLS = True EMAIL_HOST_USER = os.environ["SENDORA_API_TOKEN"] EMAIL_HOST_PASSWORD = os.environ["SENDORA_API_TOKEN"] EMAIL_TIMEOUT = 30 DEFAULT_FROM_EMAIL = "Example AB " SERVER_EMAIL = DEFAULT_FROM_EMAIL ``` Django 6.1 replaces the `EMAIL_*` settings with `MAILERS` and refuses to start with both. On 6.1, put the same values in `MAILERS["default"]["OPTIONS"]` as `host`, `port`, `use_tls`, `username`, `password` and `timeout`. `DEFAULT_FROM_EMAIL` and `SERVER_EMAIL` stay as they are. ## Set the stream, tag and metadata | Header | Sets | | -------------------------- | ------------------------------------------------------------------------------------- | | `X-Sendora-Stream` | The [stream](https://sendora.se/docs/streams) the message goes on, by its id | | `X-Sendora-Tag` | The message's tag | | `X-Sendora-Metadata-` | One metadata entry: `X-Sendora-Metadata-Customer: 4711` sets `{ "customer": "4711" }` | Without `X-Sendora-Stream`, the message goes on the server's default transactional stream. Attachments are ordinary MIME parts. Sendora also keeps `Reply-To`, `List-Unsubscribe`, `List-Unsubscribe-Post` and your own `X-` headers. It drops other headers, such as `Message-ID`, `Received` or `DKIM-Signature`, and writes its own. The API refuses these headers instead of dropping them. ## SMTP replies Sendora accepts or refuses a message before the session ends. A `250` means the message is stored and already in the log, and Sendora never refuses it after that. Delivery outcomes, such as a bounce, arrive later as events. A 5xx reply means a retry will not help. A 4xx reply means a retry may succeed. | Reply | When | | ------------------------------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | `250 2.0.0 OK: queued as ` | Accepted. The id is the one the log and the webhooks use. | | `530 5.7.0` | The client sent a message without authenticating. | | `535 5.7.8` | The key is wrong, revoked or an [account key](https://sendora.se/docs/keys), or the user name and password differ. | | `550 5.7.1` | The `From` domain is not verified, or the account is paused. On a live server, the account is not approved or without active payment. It also covers a stream in `X-Sendora-Stream` that is unknown, archived, paused or inbound. | | `550 5.1.1` | A recipient is suppressed, or a live server was given an address at `simulator.sendora.se`. The text lists the addresses. | | `550 5.6.0` | The API would refuse the message as invalid, or it breaks the [rules of a broadcast stream](https://sendora.se/docs/broadcasts#rules-of-a-broadcast-stream). The text gives the reasons. | | `552 5.3.4` | The message is over the [size limit](https://sendora.se/docs/limits#messages). | | `452 4.5.3` | The message has more recipients than [a message may have](https://sendora.se/docs/limits#messages). Split them over several messages. | | `451 4.7.0` | The per-minute limit or the monthly cap is reached. The text says when to try again. | | `451 4.3.2` | Sending is disabled for everyone for the moment. | | `451 4.3.0` | A temporary failure on Sendora's side. |