---
title: "Segments"
description: "Named groups of contacts that campaigns send to."
url: https://www.unitpost.com/guides/segments
section: Guides
updated: 2026-07-31
---
# Segments

## Segments

> Named groups of contacts that campaigns send to.

A segment is a named audience — a group of contacts a campaign can target. Each campaign sends to exactly one segment, so segments are how you decide who receives a given send.

The list shows each segment's subscribed-member count alongside its total. Only subscribed members are mailable. A segment with zero subscribed contacts is flagged, because a campaign to it can't send.

> **Empty segments block sends:** A campaign whose segment has no subscribed members is stopped before it sends — there's no one to mail. Watch for the "0 subscribed" / "Empty" badge in the list and fix the audience before scheduling.

### Archiving & deletion

Deleting a segment archives it. Archived segments disappear from pickers, but the historical record of campaigns stays intact. You can restore an archived segment, and it's permanently swept ~30 days later once unused.

> **Can't archive while actively referenced:** If a non-terminal campaign (draft, scheduled, sending) still targets a segment, archiving is blocked with a 409 — cancel or finish that campaign first.

## Related

- [Subscription topics](https://www.unitpost.com/guides/topics): Let contacts opt out of one kind of mail without leaving your list.
- [Campaigns](https://www.unitpost.com/guides/campaigns): Send a template to a segment — now or on a schedule — with server-enforced safety gates.
- [Emails](https://www.unitpost.com/guides/emails): Every individual message sent — delivery status, opens, clicks, and bounces.