Double opt-in
Double opt-in is a subscription method where a new subscriber must confirm their email address by clicking a link in a confirmation message before being added to your list. It proves the address is valid and that the person genuinely consented, producing a cleaner, more engaged and more compliant list than single opt-in.
How it works
After someone submits a signup form (the first opt-in), the system sends a confirmation email; only when they click its verification link (the second opt-in) are they added as an active subscriber. Unconfirmed addresses are never mailed.
Why it matters
Double opt-in filters out typos, fake addresses and bots, which lowers bounces and spam-trap risk. It also creates a clear consent record that helps satisfy stricter privacy regimes like GDPR — at the cost of a slightly smaller list.
How Autocloz handles it
Autocloz captures opt-in consent with an auditable record and honors opt-outs across every channel, so the permission trail behind a confirmed subscriber is preserved for compliance and deliverability.
FAQ
Is double opt-in required by law?
Not explicitly by most laws, but it is a strong way to demonstrate consent under GDPR and produces cleaner lists. Some regions and providers effectively expect it; it is best practice for marketing lists even where single opt-in is permitted.
Does double opt-in reduce list size?
Yes, somewhat — some people never confirm — but the subscribers you keep are validated and genuinely interested. The result is higher engagement, lower bounces and complaints, and better long-term deliverability than a larger unconfirmed list.
Related terms
Cold email deliverability is the share of your outbound cold emails that actually reach the recipient's inbox (not spam, not blocked). It depends on domain authentication (SPF, DKIM, DMARC), sender reputation, mailbox warmup, list hygiene and content — not just whether the email was 'sent'.
DMARC (Domain-based Message Authentication, Reporting & Conformance) is an email standard that tells receiving mail servers what to do with messages that fail SPF or DKIM checks — and sends you reports. It prevents spoofing of your domain and is now effectively required by Gmail and Yahoo for bulk senders.
SPF (Sender Policy Framework) is an email-authentication standard that lets a domain owner publish, in DNS, the list of mail servers allowed to send email on the domain's behalf. Receiving servers check the sending IP against that list to help detect spoofing and decide whether to trust the message.
DKIM (DomainKeys Identified Mail) is an email-authentication method that attaches a cryptographic signature to each message. The receiving server verifies the signature against a public key in the sender's DNS, proving the message wasn't altered in transit and genuinely came from the signing domain.