When someone joins your list, you can add them straight away, or you can send a confirmation email they must click before they are really subscribed. The second one is double opt-in, and whether you should use it is one of the small, quietly important choices in email.
It is not a rule handed down from on high — it is a trade-off, and it is worth understanding both sides.
What double opt-in actually does
It adds one step: the subscriber confirms they meant to join and that the address is really theirs. That single click filters out typos, fake sign-ups, and bots — the junk that quietly rots a list from the inside.
- Confirms the email address is valid and owned by a real person.
- Blocks bots and someone signing up another person's address.
- Proves consent, which matters under some privacy laws.
- Keeps your list cleaner, which helps you land in inboxes.
The cost you are paying
The downside is real: some people never click the confirmation. They get distracted, the email lands in spam, or they simply forget — and you lose subscribers who genuinely wanted in. Surveys suggest a noticeable share of sign-ups drop off at the confirm step.
So double opt-in trades a smaller list for a cleaner, more engaged one. That is the whole decision in a sentence.
When to turn it on
Lean toward double opt-in if you run paid ads to your sign-up, operate where consent laws are strict, or keep getting fake and mistyped addresses. Lean toward single opt-in if your traffic is warm, your freebie needs to arrive instantly, and every subscriber is precious.
Many creators start single to grow fast, then switch to double once bad addresses start hurting deliverability.
Whichever you pick, deliver instantly after
The confirmation step, if you use it, should be fast and obvious, and the reward should land the second they confirm. A confusing or slow confirm flow costs you the subscribers double opt-in was meant to protect.
You can collect sign-ups and manage your audience from your link-in-bio page at onesol.io, and keep the confirmation flow simple for the reader.