Glossary
What is double opt in?
Double opt in is a sign up process where a person who enters their email address is sent a confirmation message and is only added to the list after they click to confirm. It proves the address works and that its owner asked to join. It is common for newsletters and gated content, not for one to one sales outreach.
Published by Sellinger AI. Numbers and settings checked on 24 October 2026 against the fact register. Report an error.
How does it work?
- A person submits their email in a form.
- The system sends a confirmation email with a link.
- The person clicks the link.
- Only then is the address added, with a record of when and how.
Why use it?
| Single opt in | Double opt in | |
|---|---|---|
| List growth | Faster | Slower |
| Address quality | Typos and fake addresses get in | Only working, confirmed addresses |
| Proof of consent | Weaker | A record of the confirmation |
| Spam traps | Can be added by bots | Rarely confirmed |
Where does it fit in B2B?
For newsletters, webinars and downloads where you rely on consent, double opt in builds a clean, provable list. It does not apply to one to one outreach to business contacts, which is governed by the rules of each country; see is cold email legal. This is not legal advice.
How Sellinger handles it
Sellinger is used for conversations rather than newsletter lists, so it does not run double opt in sign ups. When a contact replies with an opt out such as STOP or unsubscribe, in English, Bulgarian or German among other forms, the contact goes on the team's suppression list, the agent stops and the lead is closed out. A weak or unclear phrase never writes the permanent record: the agent stops and a person decides.
Common questions
Is double opt in required by law?
Does double opt in reduce list size?
Should cold outreach use double opt in?
Sources and method
General email marketing practice. Sellinger behaviour from the fact register, checked 24 October 2026.
Related: Soft opt in, Spam trap, GDPR legitimate interest, Suppression list.
