Transactional email
Mail needed to complete a user action or account (receipts, resets) — not the same as a promo newsletter.
Say it out loud
“Receipts and password resets. Calling a promotion transactional to skip the rules does not work.”
A transactional message facilitates a transaction or an account relationship the recipient initiated. Marketing is promotional. The classification is decided by the content and purpose of the message, not by which template folder it was sent from, and mislabelling promotions to escape unsubscribe rules is a named enforcement target in several jurisdictions.
Now it has a promotional purpose. The safe answer is to treat it as marketing.
An abandoned-cart email is marketing everywhere, regardless of how automated it feels.
Genuinely a service message. It stops being one the moment a product block appears in it.
Yours
Nobody does this for you.
What goes wrong
Adding a “you might also like” grid to the shipping confirmation because it converts well, and continuing to send it to people who have unsubscribed. That is the exact pattern regulators cite.
The dated rule behind this
A definition is not a citation. These are the pages with the primary source, the date it was published, and what to do about it.
See also
Where this sits
Stop 2, you build the message. You choose a From address, write a subject line, and add the things the law requires to be in the message.