CSV Import¶

Import subscribers in bulk from CSV files — whether you're migrating from another email platform or uploading a list from a spreadsheet.

Importing from the Dashboard¶

Go to Subscribers in your app's dashboard
Click Import
Choose your CSV file
Select the provider format (or let MailJawn auto-detect it)
Optionally check "Treat as new subscribers" to trigger welcome automations
Click Import

Tip

Leave "Treat as new subscribers" unchecked for migrations. This prevents welcome emails from going out to people who already know your product.

Supported Formats¶

Sendy Export¶

If you're migrating from Sendy, export your subscriber list and upload the CSV as-is. MailJawn recognizes Sendy's column format automatically.

Sendy Column	MailJawn Field	Notes
`Email`	`email`	Required
`Name`	`name`	Display name
`Optin Time`	`subscribed_at` / `first_seen`	Original signup date. Format: `YYYY/MM/DD, HH:MMAM/PM`
`Status`	`status`	Mapped: `active`, `unsubscribed`, `bounced`, `complained`
`Last activity`	`last_seen`	Most recent engagement
`Country`	`custom_fields.country`	Stored as custom field
`Country code`	`custom_fields.country_code`	Stored as custom field
`Confirm Time`	`custom_fields.confirm_time`	Stored as custom field

The Joined column is also accepted as an alias for Optin Time.

Generic CSV¶

For any other source, use these column names:

Column	MailJawn Field	Required
`email`	`email`	Yes
`name`	`name`	No
`subscribed_at`	`subscribed_at` / `first_seen`	No

Note

Column matching is case-insensitive, so Email, email, and EMAIL all work.

Auto-Detection¶

MailJawn inspects your CSV headers and automatically selects the right provider format. If it finds Sendy's signature columns (Email, Name, Optin Time, Status), it uses the Sendy mapping. Otherwise, it falls back to the generic format.

Import Results¶

After import, you'll see a summary:

Stat	Meaning
Created	New subscribers added
Updated	Existing subscribers whose data was refreshed
Skipped	Rows with missing or invalid email addresses
Suppressed	Emails on your suppression list — these are not imported

How Updates Work¶

When a CSV row matches an existing subscriber (same email), MailJawn merges the data:

Name is overwritten if the CSV provides one
Dates use smart merging: first_seen keeps the earliest date, last_seen keeps the latest
Status is overwritten if the CSV provides one
Custom fields are merged additively (new keys are added, existing keys are updated, unmentioned keys are preserved)

Welcome Automation Control¶

By default, CSV imports do not trigger welcome automations — this prevents sending welcome emails to subscribers you're migrating from another platform.

To enable automations for an import:

Check the "Treat as new subscribers" checkbox before importing
Only newly created subscribers receive the welcome series (updates are always silent)

Warning

If you're migrating a large list, import first with automations off, then enable your welcome automation afterward. This ensures the backfill guard prevents old subscribers from receiving welcome emails.

API Bulk Import¶

You can also import subscribers programmatically:

POST /api/v1/projects/{project_id}/subscribers/

Send a JSON array of subscriber objects:

[
    {"email": "alice@example.com", "name": "Alice"},
    {"email": "bob@example.com", "name": "Bob"}
]

This endpoint requires an API key with subscribers:write scope. Welcome automations are never triggered for API bulk imports.

See also: Integrations > REST API for the full API reference.