Opt-in
The person actively agreed to receive your marketing email before you send it.
Say it out loud
“They asked us to email them. We did not decide for them.”
Opt-in means permission first. How strict that has to be depends entirely on the country: the EU and UK generally need a clear affirmative yes, while US federal law is built the other way round and lets you send until someone asks you to stop.
Pre-ticked is the textbook failure in the EU and UK.
Consent bundled into something else is not freely given.
"Get our newsletter" and pressed the button
This is the soft opt-in question, and it has four conditions. See below.
Consent is not transferable. Nobody agreed to hear from you.
Yours
Nobody does this for you.
What goes wrong
Treating a shipping-address field as a marketing sign-up. The person gave you an address to receive a parcel notification, which is a different purpose, and in the EU that distinction is the whole case.
Not the same as
- Double opt-in
- Double opt-in is an opt-in plus a confirmation click. Stronger evidence, same underlying permission.
The dated rules 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 1, you get the address. Someone hands you an email address, and the terms of that handover decide everything after it.