Why can't I just import everyone?

Emailing people who never opted in drives spam complaints and hard bounces, which damage your sender reputation and can get your sends blocked for everyone on your list. Importing only consented contacts is both a legal requirement in many regions and the single best thing you can do for long-term deliverability.

Do imported contacts count toward my plan?

Yes, active subscribers count toward your plan limit. The Free plan includes up to 1,000 active subscribers. If your import would exceed your tier, you can clean your list further or upgrade. See how subscriber pricing works for details.

What file format does Boostmail accept?

A standard CSV file with a header row. Include at minimum an email column; add name, phone, and custom-property columns to unlock personalization and segmentation.

What happens to duplicate or invalid rows?

Boostmail de-duplicates by email and skips rows with malformed addresses, so you don't create duplicate subscribers or import obviously bad data.

Import your subscriber list

Reviewed by Eran Betzalel, founder · 2026-06-29

You bring contacts into Boostmail with a CSV import, export from your old tool, upload the file, map the columns, and confirm consent. The most important rule: import only the subscribers who actually opted in. A list of 2,000 genuinely consented contacts will outperform a list of 20,000 scraped or purchased addresses every time, because spam complaints and bounces from non-consenting recipients quietly destroy your inbox placement for everyone.

Your Shopify customers who opted in during checkout sync into Boostmail automatically. The import flow is for everyone else, contacts living in a previous email or SMS platform. When you move that list over, take a few minutes to remove anyone who is unsubscribed, hard-bounced, or never gave permission. This keeps you compliant with regulations like GDPR and CAN-SPAM and protects the sender reputation you depend on to reach the inbox.

What to include in your CSV

Export a standard CSV with a header row. Useful columns:

Email address (required) and phone number if you plan to send SMS.
First name and last name for personalization.
Consent / subscription status so you can filter to opted-in contacts before uploading.
Custom properties, birthday, location, customer tags, or anything you want to segment on later.

Mapping and finishing

When you upload, Boostmail previews the rows and asks you to map each column to a field. Match email, name, and phone, and map any custom properties you want to keep. Columns you leave unmapped are simply ignored. Before the import runs, you confirm that everyone in the file opted in, then Boostmail adds them as active subscribers.

Remember that active subscribers count toward your plan; the Free plan covers up to 1,000. Cleaning your list before import often keeps you on a smaller, cheaper tier and improves results at the same time.

Next step

With your audience in place, you are ready to send your first campaign. For ongoing list health, see improve your sender reputation.

1

Export contacts from your old tool

In your previous email or SMS platform, export your audience as a CSV. Include email address (and phone for SMS), first and last name if you have them, and, critically, the consent or subscription-status column so you can tell who opted in.
2

Filter to consented contacts only

Before uploading, remove anyone who is unsubscribed, bounced, or never opted in. Importing only people who genuinely subscribed protects your deliverability and keeps you compliant with anti-spam and privacy rules.
3

Upload the CSV to Boostmail

In Boostmail, open Subscribers and choose Import. Select your cleaned CSV file. Boostmail reads the columns and shows a preview of the rows it found.
4

Map the fields

Match each CSV column to a Boostmail field: email, first name, last name, phone, and any custom properties you want to keep for personalization and segmentation. Unmapped columns are skipped.
5

Confirm consent and finish

Confirm that every contact in the file opted in to receive marketing from you, then start the import. Boostmail processes the file and adds the consented contacts as active subscribers, ready to receive campaigns.

Frequently asked questions

Why can't I just import everyone?: Emailing people who never opted in drives spam complaints and hard bounces, which damage your sender reputation and can get your sends blocked for everyone on your list. Importing only consented contacts is both a legal requirement in many regions and the single best thing you can do for long-term deliverability.
Do imported contacts count toward my plan?: Yes, active subscribers count toward your plan limit. The Free plan includes up to 1,000 active subscribers. If your import would exceed your tier, you can clean your list further or upgrade. See how subscriber pricing works for details.
What file format does Boostmail accept?: A standard CSV file with a header row. Include at minimum an email column; add name, phone, and custom-property columns to unlock personalization and segmentation.
What happens to duplicate or invalid rows?: Boostmail de-duplicates by email and skips rows with malformed addresses, so you don't create duplicate subscribers or import obviously bad data.