Email glossary
Plain definitions of the email marketing and deliverability terms you meet running a list, each with how it works in practice and in Mimeo.
Updated Nov 13, 2026Sending and deliverability
- Bounce typesPermanent and temporary delivery failures, and which ones to stop sending to.
- Email warm-upStarting a new domain or provider small, then raising volume as trust builds.
- List-UnsubscribeThe email header that puts an unsubscribe button in the inbox.
- Sender reputationHow far mailbox providers trust mail from your domain, and what moves it.
- Spam complaint rateThe share of your delivered email that people mark as spam.
- SPF, DKIM, DMARCThe three DNS records that prove your email really comes from your domain.
- Suppression listThe addresses your email must never reach, whatever the audience says.
- Transactional vs marketingReceipts and password resets versus newsletters and promotions, and why they stay apart.
Automation
- Broadcast emailOne message sent to a list or segment at a time you choose.
- Drip campaignA series of emails sent automatically on set delays.
- Email flowAutomation that starts when something happens and runs steps for that person.
- Flows, sequences, broadcastsOne email at a moment, a series on delays, or automation that reacts to events.
- Re-engagement and win-backEmails that bring back quiet subscribers and lapsed customers, or let them go.
- Welcome seriesThe first few emails a new subscriber gets, starting the moment they join.
Audience
- Double opt-inA signup that counts only once the person confirms their address.
- Inactive subscribersPeople still on your list who have stopped opening and clicking.
- List cleaningRemoving the addresses that can't or won't receive your email.
- Merge tagsPlaceholders filled with each subscriber's own data when an email sends.
- Preference centerA page where subscribers choose which emails they get, short of leaving.
- Tags vs segmentsLabels you put on people versus live rules that work out an audience.