It is important to understand the difference between a transactional email and a marketing email.
A marketing email is an email which target contacts (simultaneously) all together to inform them via global communications about your products, campaigns, promotions.
They can take the shape of a newsletter for example.
Unlike marketing e-mails, transactional emails are sent to a specific and unique recipient to confirm an action, a transaction or notify an event, such as:
- A registration confirmation
- A password reset confirmation
- A personalized notification
- Sending an invoice
From a practical point of view, your marketing campaigns are usually sent or scheduled manually by setting a date and time, while transactional emails are automatically triggered and sent out instantly based on an action or event.
Usually, a transactional email will use the SMTP Relay, although this is not always the case.
The SMTP Relay is not subject to different blacklists, unlike marketing emails, as those two platforms are technically separated.