Segments are saved groups of subscribers on a list, defined by conditions (tags, subscription date, engagement, custom attributes, and more). They update automatically as people match or stop matching the rules.

You cannot assign someone to a segment directly during import. Instead, import tags that describe each contact, then build segments on top of those tags. This article walks through that workflow so your list is ready to target before and after a bulk import.

Plan segments before you import

Before you upload a CSV or spreadsheet, decide how you will split the audience later:

1. List the segments you need — e.g. customers, trial-users, vip, region-west.
2. Choose one tag per segment (or per dimension) — segments usually filter on tags such as “has tag vip”.
3. Add a tags column to your import file — put the right labels on each row before upload.

Segment you want later	Tag to put in the import file	Example tags cell
Paying customers	customer	customer
Free trial	trial	trial
VIP (also a customer)	customer and vip	customer;vip
No marketing yet	(leave empty or use prospect)	prospect

Tags in imports can be separated by semicolon, comma, or pipe (customer;vip, customer,vip, or customer|vip). Mailivate creates any tag that does not exist yet.

Recommended workflow

1. Create tags (optional but helpful)

Open the list → Tags and create the labels you plan to use (customer, trial, vip, etc.). This keeps naming consistent before the file lands.

You can also let the import create tags automatically from the tags column—the names just need to match what you will use in segment conditions.

2. Import subscribers with tags

1. Prepare your file with at least email and a tags column (see Importing subscribers).
2. Go to Import subscribers, upload the file, and map columns.
3. Choose whether to replace tags on existing subscribers or merge new tags only.
4. Wait for the import to finish and fix any failed rows.

After import, open Subscribers and filter by tag to confirm counts look right.

3. Create the segment

1. Open the list → Segments → Create segment.
2. Enter a clear name (e.g. “VIP customers”).
3. Under Conditions, add rules—for most import-based segments, use Tags:
   • Has One Of — subscriber has at least one of the selected tags.
   • Contains All — subscriber has every selected tag (use for customer + vip).
   • Has None Of — subscriber does not have any of the selected tags.
   • Contains None — subscriber is missing at least one of the selected tags (stricter than “Has None Of” for multiple tags).
4. Save the segment.
5. Open the Population tab to preview who matches.

You can combine tag conditions with other rules (subscribed date, opened a campaign, custom attributes) using AND / OR groups in the condition builder.

4. Use the segment when sending

When creating a campaign or automation, choose the list, then select your segment as the audience. Only subscribers who currently match the segment conditions receive the email.

Example: three regions from one import

Import file

email	first_name	tags
alex@example.com	Alex	region-west
sam@example.com	Sam	region-east
jordan@example.com	Jordan	region-central

Three segments

Segment name	Tag condition
West	Tags → Has One Of → region-west
East	Tags → Has One Of → region-east
Central	Tags → Has One Of → region-central

Each segment’s population updates if you add subscribers or change tags later—no need to re-import for the segment definition itself.

Segments vs tags (quick reference)

	Tags	Segments
Set during import?	Yes (tags column)	No—built from conditions after import
How membership works	Stored on each subscriber	Calculated from rules
Best for	Labeling rows in your file	Campaign audience, automations, reporting
Changes when	You add/remove tags	Rules or subscriber data change

For more on tags alone, see Tags and segments.

Tips and pitfalls

• Use lowercase, consistent tag names in your spreadsheet (customer, not Customer and customer on different rows).
• One import column, many tags — combine labels in a single cell (trial;saas) when a person belongs to multiple segments.
• Segments need matching tags — if a segment is empty after import, check that tag names in the file exactly match the tags in your conditions.
• Re-imports — updating a subscriber’s tags may move them in or out of segments automatically; review Population after large updates.
• Unsubscribed contacts — segments include unsubscribed subscribers unless your conditions exclude them; respect consent when sending campaigns.

API

When integrating via the API, pass the segment UUID from the segment detail screen. Segments are evaluated at send time based on current subscriber data and tags.