List Segmentation
List segmentation groups an email audience by shared properties or activity, such as plan, location or setup progress.
List segmentation divides an email audience into groups using shared properties or activity. A SaaS team might group trial users who have not finished setup, paid customers on a particular plan, or subscribers who asked for product updates.
The useful question is what each group needs to do next. A new user who has not created a project needs different help from someone who has already invited their team.
A segment you can build in Loops
For an illustrative setup reminder, create custom contact properties named plan and setupComplete. Keep them updated from your application. Filter for plan equal to trial AND setupComplete equal to false, then save the audience as “Trial users needing setup.” These are example property names you define, not built-in Loops fields.
Send that group an email explaining the next setup step. When your application changes setupComplete to true, the contact should no longer qualify. Loops evaluates audience filters against contact data when the email sends. Its filters and segments documentation explains saved segments and the difference between matching all conditions and any condition.
Check the data before sending
Inspect sample contacts who should qualify, who should be excluded, and whose setup status is missing. Decide explicitly how missing values should behave. A missing value may mean your application has not synced the data, rather than that the person has not completed setup.
Check overlapping audiences too. A customer can qualify for a product announcement and an onboarding reminder on the same day. Coordinate those sends around what the customer needs, and preserve subscription preferences when updating contact records.
Measure the action the segment was built for
For the setup reminder, measure completed setups within a defined window, alongside unsubscribes and complaints. More opens alone would not tell you whether the reminder helped. If you test a different message, compare similar eligible users over the same period.
Use a mailing list for an explicit subscription choice, such as a newsletter. Use a segment for conditions that change with customer data. The contact properties documentation explains which fields you can store and how to update them.