Email Marketing Glossary
Plain-English definitions of the terms and concepts that matter for UK email marketers. No jargon, no padding.
Automation
Automation
Software that sends emails automatically based on triggers (like a signup, a purchase, or no engagement) rather than manually. Common examples are welcome sequences and abandoned cart flows.
Drip campaign
A series of automated emails sent on a schedule or triggered by behaviour, designed to nurture someone toward a goal over time.
Welcome email
The first automated email sent after someone subscribes. It's typically your highest-performing email and sets expectations for the relationship.
Basics
Email service provider (ESP)
The software platform you use to manage your list, design and send emails, and track results - for example Mailchimp, Brevo, MailerLite or Klaviyo.
Transactional email
Service emails triggered by a specific action you took, like order confirmations, shipping updates or password resets. They don't generally require marketing consent, but must not be used to sneak in marketing.
Compliance
Consent
Genuine, freely given, specific and informed agreement to receive marketing emails, given by a clear positive action and easy to withdraw. In the UK, PECR generally requires consent to email individuals for marketing.
Double opt-in
A signup process where a new subscriber confirms their address by clicking a link in a confirmation email before being added to your list. It improves list quality and provides evidence of consent.
GDPR
The General Data Protection Regulation. In the UK it's 'UK GDPR' - the law governing how you collect, store and use people's personal data, including email addresses.
Opt-in
The action by which someone agrees to receive your emails. Proper opt-in is a clear, positive, documented action. Pre-ticked or bundled opt-ins are not valid consent.
PECR
The Privacy and Electronic Communications Regulations - the UK law covering electronic marketing, including who you can email and what consent is needed.
Soft opt-in
In some rules, the option to email existing customers about similar products/services without fresh consent. The ICO has indicated the soft opt-in is not available for email/text marketing to individuals - check current guidance and take advice.
Unsubscribe
The process by which a recipient opts out of future marketing emails. PECR requires an easy, working way to opt out, and you must honour it promptly.
Deliverability
Bounce
An email that can't be delivered. Hard bounces are permanent (invalid address); soft bounces are temporary (full inbox, server down). High bounce rates hurt your sender reputation.
Bounce rate
The percentage of emails that couldn't be delivered. High bounce rates signal poor list hygiene and can damage deliverability, so keep your list clean.
Deliverability
The measure of whether your emails actually reach the inbox rather than the spam folder. It depends on sender reputation, authentication, content and list quality.
DKIM
DomainKeys Identified Mail - an authentication method that lets receiving servers verify an email was really sent by your domain and wasn't tampered with. Set it up with your email platform.
DMARC
Domain-based Message Authentication, Reporting and Conformance - a policy that tells receiving servers what to do with emails that fail SPF and DKIM checks, and gives you reports on authentication.
Email deliverability
The ability of your emails to land in the inbox rather than spam. Healthy deliverability comes from authentication, good reputation and relevant, low-complaint email.
Hard bounce
A permanent delivery failure, usually because the address is invalid or doesn't exist. Remove or suppress hard-bouncing addresses to protect your reputation.
List hygiene
Keeping your subscriber list clean by removing hard bounces, inactive and unsubscribed contacts. It protects deliverability and keeps engagement healthy.
Sender reputation
The score mailbox providers assign to your sending domain and IP based on spam complaints, bounces and engagement. It strongly influences whether your email reaches the inbox.
Spam complaint
When a recipient marks your email as spam. High complaint rates significantly damage deliverability, so keep expectation-setting and unsubscribing easy.
SPF
Sender Policy Framework - an authentication record that tells receiving servers which servers are allowed to send email for your domain. Essential for deliverability.
Ecommerce
List Building
Metrics
Click-through rate (CTR)
The percentage of recipients who clicked at least one link in your email. It measures how compelling your content and calls to action are.
Open rate
The percentage of delivered emails that were opened. It's an imperfect metric (opens can be inflated by previews), but useful as a relative signal of subject lines and reputation.
Strategy
Personalisation
Tailoring email content to individual recipients using data like name, purchase history or behaviour. Relevance beats simply using the first name.
Segmentation
Dividing your list into smaller groups by shared characteristics - behaviour, demographics, purchase history - so you can send more relevant messages to each group.