Email segmentation strategy: 5 behaviour-based segments to build first
Five segments built on what people did, what to send each one, and the sender requirements that keep your emails out of spam.
Segment your list by behaviour, not demographics. Start with five groups: new leads, no-shows, engaged but not converted, past customers and contacts who have gone quiet. Send each group a message that fits its situation, and protect deliverability by authenticating your domain and suppressing people who never engage.
- What someone did last week predicts what they need next better than their job title or city.
- Gmail requires SPF or DKIM for all senders, and SPF, DKIM, DMARC and one-click unsubscribe for bulk senders.
- Keep your spam complaint rate below 0.3% in Google Postmaster Tools.
- Clicks and replies are more reliable engagement signals than opens.
Key terms explained (11)
- CRM
- Customer relationship management software: one place that stores your contacts, conversations, appointments and deals. GoHighLevel and HubSpot are examples.
- CASL
- Canada’s Anti-Spam Legislation: the law that sets the rules for sending commercial emails and text messages in Canada.
- SPF
- Sender Policy Framework: a setting on your domain that lists which services are allowed to send email on your behalf.
- DKIM
- DomainKeys Identified Mail: a digital signature added to your emails so inboxes can check they really came from you and weren’t changed.
- DMARC
- A domain setting that tells inboxes what to do with emails that claim to be from you but fail the SPF or DKIM checks.
- DNS
- Domain Name System: the settings for your domain that tell the internet where your website and email are hosted.
- Conversion
- When a visitor does what you want them to do, such as booking, buying or filling in a form.
- Open rate
- The share of people who opened an email. Apple Mail can register opens automatically, so treat it as a rough guide.
- Click rate
- The share of people who clicked a link in an email. A more reliable sign of interest than opens.
- Deliverability
- How reliably your emails land in the inbox instead of the spam folder.
- Segment
- A group of contacts who share a behaviour or trait, so they can get messages that fit them.
What is email segmentation?
Email segmentation is dividing your list into smaller groups so each group receives messages that match its situation. The alternative is the “blast”: one email to everyone, relevant to few. Segmenting improves results for a simple reason. A person who booked a call yesterday and a person who bought two years ago are not waiting for the same email.
Why segment by behaviour instead of demographics?
Demographic segments (city, industry, job title) describe who someone is. Behavioural segments describe what they did: filled in a form, missed an appointment, clicked a pricing link, bought, stopped opening. Two people with the same job title can be at opposite ends of a buying decision. Behaviour tells you where they are, and most CRMs and email tools already record it.
Which five segments should I build first?
| Segment | Who is in it | Goal | What to send |
|---|---|---|---|
| New lead | Joined in the last 14 days, not booked | First conversation | Three short emails: who you are, the most common question answered, a clear invitation to book |
| No-show | Booked, did not attend | Reschedule | One friendly email with a reschedule link, sent the same day, and one follow-up |
| Engaged, not converted | Clicked in the last 30 days, never bought | Decision | A specific case story, pricing clarity or a time-limited offer |
| Past customer | Bought before | Review, referral, repeat | Review request, maintenance reminders, referral ask |
| Gone quiet | No clicks or opens in 90 days | Re-engage or remove | One “still interested?” email, then suppress non-responders |
Build each segment as a saved filter that updates automatically, so contacts move between groups as their behaviour changes.
Which segment is this person in?
Pick what the subscriber did most recently.
What should I send each segment?
Write for one person in that situation. A no-show email should not sound like a newsletter:
Subject: Want to pick another time?
Hi [first name], we missed you today. No problem at all. If you'd still like to talk through [service], here's my calendar: [link]. If the timing isn't right, just reply and let me know.
For the engaged group, look at what they clicked. Someone who opened the pricing page twice needs pricing clarity. Someone who read three case studies needs a reason to act now. Short, plain emails from a named person usually get more replies than designed templates, because they read like a conversation.
What are the email sender requirements?
Segmentation only helps if the email reaches the inbox. Google's email sender guidelines set the baseline for sending to Gmail accounts:
- All senders must authenticate with SPF (Sender Policy Framework) or DKIM (DomainKeys Identified Mail) and keep spam rates reported in Postmaster Tools below 0.3%.
- Bulk senders, meaning 5,000 or more messages a day to Gmail addresses, must set up SPF and DKIM and DMARC (a domain email policy), and must support one-click unsubscribe on marketing messages.
Even if you send far less than that, set up all three. Your email platform provides the DNS (your domain's settings) records, and MXToolbox can confirm they are published correctly. Then add your domain to Google Postmaster Tools to watch your spam rate and reputation.
The law applies as well. In Canada, CASL requires consent, sender identification and an unsubscribe mechanism for commercial messages. Keep a record of how and when each contact opted in.
Why should I stop emailing people who never open?
Mailbox providers judge senders partly by how recipients react. A large group of people who ignore or delete your emails pulls down the reputation of everything you send, including the emails to your best customers. A sunset policy fixes this: after 90 days of no engagement, send one re-engagement email, then stop marketing to anyone who does not respond. Your list gets smaller and your results get better.
One caution on measurement. Privacy features in some mail apps load emails automatically, which inflates open rates. Use clicks, replies and bookings to decide who is engaged.
How do I measure whether segmentation is working?
- Per segment: click rate, reply rate and the one conversion that segment exists for (booking, reschedule, review, repeat purchase).
- Across the list: unsubscribe rate, spam complaint rate and revenue or bookings attributed to email.
Review monthly. If a segment's conversion is flat, change the message before you change the segment.
Tools for the job
| Tool | Use it for | Cost |
|---|---|---|
| Mailchimp | Email campaigns and basic behavioural segments | Free plan |
| Klaviyo | Advanced segmentation for e-commerce | Free plan |
| ActiveCampaign | Automation and CRM-based segments | Paid |
| MailerLite | Simple campaigns and automations | Free plan |
| GoHighLevel | Segments built from pipeline stages and tags | Paid |
| Google Postmaster Tools | Spam rate and domain reputation | Free |
| MXToolbox | Check SPF, DKIM and DMARC records | Free |
Plans and pricing change. Check each tool's site for current details.
Frequently asked questions
How many segments do I need?
Start with five. Add a segment only when you have a different message for that group. More segments without different content adds work, not results.
How big does my list need to be to segment?
Any size. Behavioural segments work with a hundred contacts, because the point is relevance, not statistics.
What is the difference between a segment and a tag?
A tag is a label you attach to a contact. A segment is a saved filter that can combine tags, fields and behaviour, and updates automatically as contacts change.
Do I need DMARC if I send fewer than 5,000 emails a day?
Gmail only requires it for bulk senders, but setting it up protects your domain from spoofing and helps deliverability. It is worth doing at any volume.
Related playbooks
Browse every playbook on email marketing, or see all marketing playbooks.
Sources
- Email sender guidelinesGoogle Workspace / Gmail Help
- Canada's anti-spam legislationCRTC
- Postmaster ToolsGoogle
Remar Catapang is a full-funnel marketing strategist based in Ontario, Canada. He has worked in marketing since 2020 and continues to lead search, CRM automation, web, paid media and experiential campaigns for businesses in Canada, the United States, Australia, Egypt and the Philippines. His playbooks are based on that ongoing work. Questions about this playbook: remarcatapangjr@gmail.com
