Email types & metrics
Double opt-in
A signup flow that requires a subscriber to confirm their email address via a confirmation link before they’re added to a marketing list.
How it works
Someone enters their email address, you send a confirmation email, and they’re only added to your list once they click the link. Until then they stay pending.
The benefits
- Typos and fake addresses never reach your list.
- Bots and malicious signups can’t flood your list with other people’s addresses.
- Typo spam traps are far less likely to get in.
- You have clear proof of consent, which helps under GDPR and similar laws.
The trade-off
Some people never click the confirmation link, so your list grows more slowly. The contacts you keep are more engaged, though, and for most senders better deliverability more than makes up for the smaller list.
Let MailCraft handle the details
Authentication, bounces, complaints and suppression are built in. Start free with 3,000 emails a month, no credit card required.
Start freeRelated terms
Full glossaryDeliverability
Spam trap
An email address with no real owner, used by mailbox providers and blocklists to catch senders with poor list hygiene — sending to one is a strong negative signal.
Email types & metrics
Marketing email
Email sent to promote something — a product update, offer, or newsletter — typically requiring recipient consent and a working unsubscribe mechanism.
Deliverability
Engagement rate
How often recipients open, click, or otherwise interact with your email — a primary signal mailbox providers use to decide future inbox placement.