What is email marketing?
Email marketing is the practice of sending commercial or informational messages to a list of subscribers who have given their explicit permission to receive them. The word “permission” is the operative one — it distinguishes email marketing from cold email (unsolicited outreach to prospects who didn’t subscribe) and from transactional email (receipts, password resets, shipping notifications).
In 2026, email marketing encompasses:
- Broadcast campaigns: A newsletter sent to your entire list (or a segment of it) at a scheduled time
- Drip campaigns: Automated sequences triggered by subscriber behaviour (signup, purchase, inactivity)
- Lifecycle email: Staged messaging across the customer journey — welcome, onboarding, retention, win-back
- Transactional marketing: Receipts and notifications with promotional content added (e.g., “Your order shipped — here’s what others bought”)
How email marketing differs from related terms
This is where most guides are unclear. The distinctions matter because they map to different tools, compliance requirements, and success metrics.
| Type | Permission | Tool | Compliance |
|---|---|---|---|
| Email marketing | Explicit opt-in | Mailchimp, Brevo, Klaviyo | CAN-SPAM, GDPR |
| Cold email | None (prospect research) | Apollo, Instantly, Lemlist | CAN-SPAM (US), GDPR (EU) — stricter |
| Transactional email | Implied (customer) | SendGrid, Postmark, Mailgun | Standard data protection |
| Newsletter | Explicit opt-in | Same as email marketing | Same |
The most common confusion: “newsletter” is not a separate category — it’s a format within email marketing. A newsletter sent via Mailchimp to opted-in subscribers is email marketing. A cold outreach email sent via Apollo to scraped contacts is cold email, even if it’s formatted like a newsletter.
Does email marketing still work in 2026?
Yes — by most available evidence, email marketing delivers the highest ROI of any digital marketing channel.
The commonly cited figure is $36 return for every $1 spent. This is aggregated across industries and inflated by B2C ecommerce attribution (Klaviyo’s customer data, which shows email driving 15–25% of ecommerce revenue for the stores using their platform). Your individual return will vary significantly.
What’s changed since 2022:
- Apple Mail Privacy Protection (MPP): Open rates are now unreliable as engagement metrics for Apple Mail users. Klaviyo, ActiveCampaign, and Brevo all filter out MPP-inflated opens and recommend using click-through rate and revenue per recipient as primary metrics instead.
- Gmail and Yahoo bulk-sender requirements (February 2024): DKIM, SPF, DMARC, and one-click unsubscribe are now required for bulk senders. Platforms like Brevo and Mailchimp implement these automatically on verified domains.
- AI-generated content at scale: Email inboxes are more crowded in 2026. Subject line differentiation and send-time optimisation matter more.
The five types of email marketing campaigns
1. Welcome series
The welcome series is the most important automation for most businesses: 3–7 emails sent to every new subscriber in the first 2 weeks. Industry data consistently shows that new subscribers are most engaged in their first 48 hours. Welcome series typically generate 3–4x higher open rates than broadcast newsletters.
2. Promotional campaigns
Broadcast emails to your list (or a segment) promoting a specific offer, product, or event. These are the “newsletters” most people think of when they hear “email marketing.”
3. Abandoned-cart workflows
Automated emails sent when a shopper adds items to a cart but doesn’t complete checkout. Klaviyo and Omnisend are purpose-built for this; it’s the highest-ROI automation for ecommerce.
4. Re-engagement campaigns
Emails targeting dormant subscribers — typically those who haven’t opened in 90+ days. Goal: get them to confirm continued interest, or remove them from the list.
5. Transactional marketing
Order confirmations, shipping notifications, and receipts with promotional content. Brevo and SendGrid handle both transactional and marketing email from the same account — most other platforms separate them.
What you need to get started
- An email marketing platform — Brevo (free), MailerLite (free), or Mailchimp (250 contacts free, limited). Choose based on list size and send frequency.
- A list-building mechanism — signup form on your website, lead magnet, or in-person collection
- A sending domain — ideally your own domain (not Gmail/Yahoo) with DKIM and SPF configured
- At minimum: a welcome email — the first thing to build before you have any subscribers
The cost reality most beginner guides skip
Most “what is email marketing” guides gloss over cost. Here’s the realistic picture for 2026:
Starting from zero: £0/month on Brevo (unlimited contacts, 300 sends/day) or MailerLite (1K contacts, 12K sends/month). Both include automation.
At 1,000 subscribers: Brevo free (if sending less than 300/day) or MailerLite free. Mailchimp would cost $13/mo — avoid it at this size.
At 5,000 subscribers: Brevo Starter £9/mo or MailerLite Growing Business £32/mo. Mailchimp Standard would be $75/mo — a 4–8x premium for comparable features.
At 50,000 subscribers: The economics depend heavily on your send frequency and use case. See the pricing comparison guide.
The billing model — per-contact vs per-send — is the single most important decision you make when choosing a platform. It determines your cost more than any feature comparison.
Compliance: what the law actually requires
Email marketing in the UK/US/EU must comply with:
CAN-SPAM (US):
- Physical mailing address in every email
- Accurate From name and subject line (no deception)
- One-click unsubscribe mechanism
- Honour unsubscribes within 10 business days
GDPR (EU/UK):
- Lawful basis for processing (consent is the standard for marketing)
- Double opt-in is best practice (not legally required but strongly recommended)
- Right to erasure (delete on request)
- Clear privacy policy
Gmail/Yahoo 2024 requirements:
- DKIM authentication
- SPF record
- DMARC policy
- One-click unsubscribe (List-Unsubscribe-Post header)
Every major email marketing platform now handles the Gmail/Yahoo requirements automatically when you authenticate your sending domain. The compliance burden for most small businesses is low.
Next steps
- Start free: Brevo (unlimited contacts) or MailerLite (1K contacts, automation included)
- Take the quiz: 60-second decision wizard if you’re not sure which platform fits
- Read the comparison: Best email marketing platforms 2026 — tested and ranked by fit
Or continue learning: How to choose an email marketing platform