Import Email Addresses
How to import email addresses from your server to use OneSignal Email Messaging
This guide explains how to upload a CSV list of email addresses through the dashboard or manually add emails if needed. Other options include:
- (Recommended) Frontend SDK Email SDK Methods.
- Create user or Create subscription API.
- Email & Phone Number Web Prompt - Allows a user to include their own email address through your website.
Duplicate Email Records
OneSignal will automatically remove duplicate email subscriptions. If the email subscription is marked as unsubscribed, it will continue to be marked unsubscribed unless updated.
Import Emails through Dashboard
Within Audience > Subscriptions you can import a CSV list of email addresses or add email addresses manually.
CSV Upload
CSV Email Upload Requirements
- Must have
- Limited to UTF-8 Encoding
- Columns must be unique
- No quotes
- Commas only, no semi-colons
The CSV must have an email
column containing the addresses. It is recommended to include the external_id
column to identify the user that owns the email address. See Aliases & External ID for details.
If you want to include email addresses that have opted-out of receiving messages, set the subscribed
column to yes
or no
. Without this column, it defaults to all addresses opted-in (yes
).
The CSV can include Data Tags for segmentation and Message Personalization as well as update the subscription status. Set the tag key
for the column and the value
under it.
Example CSV:
email,external_id,subscribed,group,status,first_name,awesome_level,other_tag_keys

Navigate to Audience > Subscriptions > Update/Import Users.
Under "Import email(s)" select Upload CSV. There is also a CSV Template you can download to check your format.

Which columns would you like to import as tags?
Checked columns will be imported as tags. Uncheck the columns you do not want set as tags.
Advanced Settings
If you want to create a segment to send messages to this list, toggle on the Automatically create a segment for this import to set a new tag and create a segment for these users.
Delete identifier and tag values if columns are empty
Check this option if you want to delete the tag on the user if the key is present on the user and no value set in the CSV.

Review and click Confirm and Update when ready to import. You will get an email to the current address when the upload is finished.
Manually Add Emails
Navigate to Audience > Subscriptions > Arrow next to Update/Import Users > Manually Add Emails to open a new modal where you can add an individual user's email and tag data.


Done!
Once you've imported your emails, go back to Email Quickstart to determine if you have any steps left.
Updated about 1 month ago