SMTP relay

Connection settings

Setting	Value
Host	`smtp.buzzmarkapp.com`
Port	`587` (recommended) or `2525` if your network blocks 587. There’s no implicit-TLS port 465.
Encryption	STARTTLS, required. Connect in plain text, then upgrade - in most libraries that’s `tls` / `secure: false` + STARTTLS, not `ssl`.
Authentication	`PLAIN` or `LOGIN`
Username	Your hive token (any value works - only the password is checked)
Password	Your hive token, `bzm_srv_…`
Max message size	25 MB, including attachments

What a session looks like SMTP

S: 220 smtp.buzzmarkapp.com ESMTP
C: EHLO app.acme.com
S: 250-smtp.buzzmarkapp.com
S: 250-STARTTLS
S: 250 ...
C: STARTTLS
S: 220 Go ahead
   (TLS handshake - AUTH is only offered from here on)
C: EHLO app.acme.com
S: 250-AUTH PLAIN LOGIN
S: 250 ...
C: AUTH PLAIN AGJ6bV9zcnZfLi4uAGJ6bV9zcnZfLi4u
S: 235 2.7.0 Authentication successful
C: MAIL FROM:<hello@acme.com>
C: RCPT TO:<customer@example.com>
C: DATA
   ...
S: 250 Message accepted as f5ab446c-18ad-4db4-b747-8e1ba70ec72d

The SMTP password is the hive’s API token - the same one the REST API uses - so mail sent over SMTP lands in that hive’s message log. Create or rotate it on the hive’s settings page in the dashboard; it’s shown once.

AUTH is only offered after STARTTLS, so a password is never sent unencrypted. If your client says the server doesn’t support authentication, it didn’t start TLS.
Rotating the token in the dashboard stops the old one working immediately - update your mailer at the same time.

How your email is read

Buzzmark reads the message you submit and treats it exactly like an API send:

From the message you submit

NameDescription

From header

header required

The sender. Its domain must be verified on your workspace. If the header is missing, the envelope sender (MAIL FROM) is used.

To / Cc headers

addresses

The visible recipients.

Envelope recipients

RCPT TO

Anyone you sent to who isn’t in To or Cc is treated as Bcc - so normal Bcc from your mail library just works.

Reply-To, Subject

headers

Kept as they are.

HTML and text parts

MIME required

The first HTML part and the first plain-text part become the bodies. You need at least one.

Attachments

MIME

Kept, including inline images with a Content-ID. Same limits as the API.

X- headers

headers

Custom headers starting with X- are passed through. Other headers are set by Buzzmark.

Tags and metadata can’t be set over SMTP. If you want to filter by Tag or get your own Metadata back in webhooks, send with the API instead.

Sending rules

Everything that applies to the API applies here:

The From domain must be verified on your workspace.
Recipients on the hive’s suppression list (after a hard bounce or spam complaint) are refused.
Your account’s per-minute send rate and monthly allowance apply.
Open and click tracking follow the hive’s settings.
Every message appears in the hive’s message log and triggers your webhooks, just like an API send.
A brand-new account’s first few emails may be held briefly for review before they go out.

SMTP replies

What the server answers when you hand over a message, and what your mailer should do:

Responses

250 Message accepted as {MessageID} - accepted. The id is the same MessageID as in the message log and webhooks.
451 4.3.0 Temporary failure, retry later - you’re over your per-minute rate, or something went wrong on our side. Your mailer should retry later; most do automatically.
530 Authentication required - you tried to send without logging in. Start TLS, then authenticate.
535 Authentication failed - the token is wrong, revoked, or belongs to a deleted hive.
550 5.7.1 … - refused, with the reason: an unverified From domain, a suppressed recipient, no body, a blocked account or a used-up free allowance. Don’t retry until you’ve fixed it.

Quick test

swaks is the quickest way to check your settings from a terminal. A successful run ends with 250 Message accepted as …, and the message shows up in the hive’s message log straight away.

swaks shell

swaks \
  --server smtp.buzzmarkapp.com --port 587 -tls \
  --auth PLAIN \
  --auth-user bzm_srv_... --auth-password bzm_srv_... \
  --from hello@acme.com \
  --to customer@example.com \
  --header "Subject: Hello from SMTP" \
  --body "It works."

Frameworks

Any SMTP client works. Use port 587 with STARTTLS (often labelled tls), and the hive token as both username and password. Keep the token in an environment variable rather than in your code.

Laravel - set the mail variables in .env; Mail::to(...)->send(...) then goes through Buzzmark.
Node.js - Nodemailer with secure: false and requireTLS: true.
Python - the standard library’s smtplib; call starttls() before login().
Django / Rails - the built-in SMTP backends.

Laravel .env

# .env
MAIL_MAILER=smtp
MAIL_HOST=smtp.buzzmarkapp.com
MAIL_PORT=587
MAIL_ENCRYPTION=tls
MAIL_USERNAME=bzm_srv_...
MAIL_PASSWORD=bzm_srv_...
MAIL_FROM_ADDRESS=hello@acme.com
MAIL_FROM_NAME="Acme"

Node.js Nodemailer

import nodemailer from "nodemailer";

const transport = nodemailer.createTransport({
  host: "smtp.buzzmarkapp.com",
  port: 587,
  secure: false,          // starts plain, then upgrades with STARTTLS
  requireTLS: true,       // refuse to send if STARTTLS fails
  auth: { user: "bzm_srv_...", pass: process.env.BUZZMARK_TOKEN },
});

await transport.sendMail({
  from: "Acme <hello@acme.com>",
  to: "customer@example.com",
  subject: "Your receipt",
  html: "<p>Thanks for your order!</p>",
  text: "Thanks for your order!",
  headers: { "X-Order-Id": "1234" },
});

Python smtplib

import os, smtplib
from email.message import EmailMessage

msg = EmailMessage()
msg["From"] = "Acme <hello@acme.com>"
msg["To"] = "customer@example.com"
msg["Subject"] = "Your receipt"
msg.set_content("Thanks for your order!")
msg.add_alternative("<p>Thanks for your order!</p>", subtype="html")

token = os.environ["BUZZMARK_TOKEN"]
with smtplib.SMTP("smtp.buzzmarkapp.com", 587) as smtp:
    smtp.starttls()
    smtp.login(token, token)
    smtp.send_message(msg)

Django settings.py

# settings.py
EMAIL_BACKEND = "django.core.mail.backends.smtp.EmailBackend"
EMAIL_HOST = "smtp.buzzmarkapp.com"
EMAIL_PORT = 587
EMAIL_USE_TLS = True
EMAIL_HOST_USER = os.environ["BUZZMARK_TOKEN"]
EMAIL_HOST_PASSWORD = os.environ["BUZZMARK_TOKEN"]
DEFAULT_FROM_EMAIL = "Acme <hello@acme.com>"

Rails Action Mailer

# config/environments/production.rb
config.action_mailer.delivery_method = :smtp
config.action_mailer.smtp_settings = {
  address: "smtp.buzzmarkapp.com",
  port: 587,
  user_name: ENV["BUZZMARK_TOKEN"],
  password: ENV["BUZZMARK_TOKEN"],
  authentication: :plain,
  enable_starttls: true
}