This guide is for newsletter writers, bloggers and small business owners with a list somewhere between a few hundred and a few thousand subscribers. Segmentation means sending different messages to different parts of your list. Done well, it makes every email more relevant. Done badly, it becomes a tangle of groups you cannot keep up with. Below you will find the segments worth starting with, how to collect the data behind them, where the menus live in three common platforms, and a simple way to deal with subscribers who have gone quiet.
Contents
Why relevance matters to inbox providers
Segmentation is not only about better results from each campaign. Google’s email sender guidelines tell senders to mail only people who want their messages, noting that recipients who opted in are less likely to report spam. They also advise starting with a low volume to engaged users and increasing it slowly, and they suggest periodically asking recipients whether they want to stay subscribed and considering unsubscribing people who do not open or read your messages.
The same guidelines tell senders to keep the spam rate shown in Postmaster Tools below 0.3%, and recommend staying below 0.10% and never reaching 0.30% or higher. The practical point for a small list is simple: sending relevant mail to people who still want it keeps complaints low. Segments are the tool that lets you do that on purpose.
Five segments to consider first
You do not need all of these. Pick the one or two that match a real difference in what you would send.
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| Segment | What it groups | Typical use |
|---|---|---|
| Engagement | People who recently opened or clicked versus people who have not | Protect sender reputation; run re-engagement |
| Signup source | Which form, page or lead magnet brought them in | Match the welcome message to what they asked for |
| Interests | Topics people chose or clicked on | Send topic-specific issues or offers |
| Purchase or customer status | Customers versus subscribers who have not bought | Stop pitching what they already own; send customer-only updates |
| Location | Country, region or time zone | Local events, shipping notices, sensible send times |
Engagement
This is the most useful segment for almost every list because it supports the sunset process described later. Define it in terms you can act on, such as “opened or clicked an email in the last 90 days”. One caution: open tracking is imperfect, because some mail apps load images automatically or block them, so treat opens as a rough signal and give clicks more weight.
Signup source
Someone who joined through a checklist download expects something different from someone who joined from a blog sidebar. Recording the source lets you tailor the first emails. If you are building that first series, see our guide to an email welcome sequence for a new newsletter.
Interests, customer status and location
Interests work best when subscribers tell you directly, through a form choice or by clicking a topic link. Customer status is valuable because it separates “needs persuading” from “needs support or a thank-you”. Location matters mainly when you have physical events, regional pricing or shipping cut-offs; otherwise it is usually not worth the extra form field.
How to collect the data
Segments are only as good as the information behind them. There are three practical ways to gather it without making signup feel like a questionnaire.
- Signup form fields. Ask for the minimum. An email address is enough for most lists. Add one optional question, such as a topic checkbox, only if you will genuinely use the answer. Do not pre-check opt-in boxes; Google’s guidelines advise avoiding opt-in forms that are checked by default and note that some regions restrict automatic opt-in.
- Tags applied by forms or automations. Use a separate form per lead magnet or page, with each form adding its own tag. This captures signup source automatically.
- Link clicks. A link in an email such as “Want more on this topic?” can add an interest tag when clicked. This shows interest through behaviour rather than a form answer.
Where the controls live in three platforms
This reflects the vendors’ own help pages as published when this article was written.
Kit (formerly ConvertKit)
Kit’s help centre describes tags as labels for fixed groups of subscribers that stay on a subscriber unless intentionally removed, and segments as fluid groups of subscribers who meet certain filter conditions, with people added or removed automatically as they start or stop meeting them. Both appear in the right sidebar of the Subscribers page, next to All Segments and All Tags. Subscribers can be tagged manually, or automatically through opt-in forms, Visual Automations or Link Triggers. Segment filter conditions include tags, opt-in sign-ups, location and sign-up dates.
Kit’s guidance on choosing: use a tag when you need a fixed group or want to trigger a Visual Automation or Automation Rule, since segments cannot trigger those. Use a segment when grouping is hard with tags alone, for example combining subscribers with different tags or grouping by subscribe date. Both can be used to send broadcasts.
MailerLite
MailerLite’s help page lists these steps: open the Subscribers page, switch to the Segments tab, click Create segment, then click Create to build one from scratch or pick a pre-made filter from the segment library. Name it, add filters, choose “and” or “or”, and click Save changes. Available filters include Groups, Fields, Location, Signup date, Signup source, Time zone, Campaigns, Email actions, Last emailed, and purchase filters such as Has purchased product. Segments update automatically as subscribers start or stop matching.
MailerLite separates segments from groups. Its help article says groups (also called interest groups or tags) have no rules and are changed manually, by an automation action, or by an integrated app, while segments are rule-based. Both can be used as campaign recipients or exclusions.
Mailchimp
Mailchimp’s segmentation help page says segments can be created in the email builder, the SMS builder or the contact table, and that you should save a segment in the contact table if you plan to target those contacts regularly. Conditions combine with And or Or. For email, Mailchimp removes contacts who are not subscribed. Tags are handled separately in Mailchimp, so check its tag help for the current steps.
How to avoid over-segmenting a small list
On a small list, every extra segment splits an already small audience and adds work. A few guardrails help.
- Create a segment only when you will send it something different. If the email would be identical, you do not need the segment.
- Start with two or three. Engagement plus signup source covers most needs.
- Prefer dynamic segments built from a small, consistent set of tags over dozens of one-off tags. Write the tag names and their meanings down in one place.
- Avoid stacking many conditions. A segment of 12 people is rarely worth a separate campaign.
- Review quarterly and delete segments and tags you have not used.
A simple re-engagement and sunset process
Sending to people who no longer read your mail does nothing for you, and Google’s guidelines explicitly suggest considering removing people who do not open or read. A straightforward approach:
- Define inactive. For example, no opens or clicks in the last 90 days, and subscribed for longer than that. Exclude brand-new subscribers.
- Build the segment. Use your platform’s activity filters, such as Campaigns and Email actions in MailerLite or an activity-based segment in your own tool.
- Send one or two re-engagement emails. Be direct: say you have noticed they have not been reading, offer one clear click to stay, and make unsubscribing easy.
- Tag those who click. They move back into your active segment.
- Remove or suppress the rest. Unsubscribe or archive them. Keep a note of the date and reason so you can explain it later.
A smaller list of people who want your emails is easier to keep relevant than a larger one padded with silence. For broader sending habits, see our post on email marketing tips.
Key takeaways
- Start with engagement and signup source; add others only when you will send something different.
- Collect data through minimal form fields, one tag per form, and link clicks.
- Tags are fixed labels; segments are rule-based and update on their own (Kit, MailerLite).
- Google’s sender guidelines favour opted-in, engaged recipients and low spam rates.
- Run a regular sunset: define inactive, re-engage once or twice, then remove.
FAQ
How big should a list be before I segment?
There is no official threshold in the help pages reviewed. A sensible rule is to segment once you have a real reason to send different content, even on a small list. Begin with engagement.
Should I use tags or segments?
Use tags to record facts about a subscriber, such as which form they used. Use segments to turn those facts, plus activity, into a sendable group. In Kit, tags are also required to trigger automations.
Is it safe to delete inactive subscribers?
Removing people who have not engaged after a re-engagement attempt is consistent with Google’s suggestion to consider unsubscribing non-openers. Export the list first if you want a record.
Does segmenting guarantee better open rates?
No. Results vary by list, audience and content, and the platform help pages make no such promise. Segmentation improves relevance; measure the effect on your own list.
