Dispatching transactional emails via SMTP

Jaroslav Bouška Jaroslav Bouška
5. September 2025

If you need full control over transactional emails sent from your online store or an app that allows dispatch only via SMTP, Boldem provides a reliable solution in the form of secure SMTP servers for instant and dependable dispatch of transactional messages. Below you’ll find instructions on how to set it up.

Prerequisites

  • Fully activated account with a verified domain.
  • Active E-mailing plan or higher.
  • Account created for SMTP verification.

Create SMTP Account

To send messages via Boldem’s SMTP server, you need to create an SMTP verification account.

  1. Log in to Boldem app.
  2. Go to Settings and select Domains.
  3. Click a fully verified domain to view its details.
  4. Select the SMTP Verification tab.
  5. Click Create SMTP user.
  6. Enter a username. It should be a mailbox on your domain that already exists.
  7. Confirm the dialog to generate the login credentials. Save the username and password in a secure place.

Using Boldem SMTP

When setting up your app or online store, use the following information:

SMTP server address: smtp.boldem.cz

Username: (created in the Boldem app)

User password: (you created it in the Boldem app)

Ports:

  • 25: The port supports connections with or without STARTTLS.
  • 465: Port supports only secure TLS connections.
  • 587: Port supports connections secured with STARTTLS or unsecured.

Emails sent via Boldem SMTP will include everything needed for perfect deliverability — required headers, a DKIM signature, and the like.

Dispatch settings

When creating emails, you can also use the following headers to configure dispatch settings.

HeaderDescription
x-Boldem-track-openstrue/false, default is true, enables tracking of email open rate using a tracking pixel
x-Boldem-track-clickstrue/false, default is true, enables tracking of click-throughs from emails.
x-Boldem-tagsText, 100 characters, used to tag emails for traceability; available in both the user interface and in webhook callbacks.
x-Boldem-is-bulktrue/false, default is false, used to indicate that this is a bulk
email (see What is the difference between transactional and bulk email)
X-Boldem-Allow-Unsubscribetrue/false, default true, used only in combination with the header “x-boldem-is-bulk”
Custom headerYou can provide custom headers for better traceability*

* the following headers are not preserved in their original state: “from”, “to”, “cc”, “bcc”, “reply-to”, “date”, “subject”, “message-id”, “mime-version”, “dkim-signature”, “x-mailer”, “x-mailer-type”