Uploading a Suppression List for Justuno Spotlight

Justuno Spotlight lets you upload a suppression list — a file of identifiers you want Spotlight to exclude. You deliver this file to Justuno over SFTP (SSH File Transfer Protocol), a secure, encrypted way to send files.

This article covers how to find your credentials, generate the API key used as your SFTP password, and upload your file.

Important: the SFTP endpoint is upload-only

Before you begin, understand one key behavior:

You cannot query, list, download, or verify files once they are uploaded. The SFTP endpoint accepts your file and hands it off for processing — it does not let you browse or read back what's on the server. Commands like ls    or get    will not return your uploaded files.

Because of this, you should:

• Keep your own local copy of every suppression file you upload.
• Track your uploads yourself (filename, date, and what it contained), since you can't inspect them afterward.
• Treat each upload as final — re-upload a corrected file rather than expecting to fix one in place.

Before you start

You'll need:

1. An SFTP client — the sftp    command line tool (built into macOS and Linux, available on Windows), or a GUI client such as FileZilla, Cyberduck, or WinSCP.
2. Your SFTP credentials — a host, a username, and a password (see below).
3. Your suppression file, formatted correctly (see File format below).

Your SFTP credentials

Username format

Your username is your domain ID followed by.  

Step 1 — Find your domain ID

Your domain ID identifies your Justuno account and forms the first half of your SFTP username.

1. Open the Justuno Portal.
2. Go to Account Settings → Embed Code.
3. You'll find your domain id is listed as the Token ID   on the right hand side.

Step 2 — Generate your API key (SFTP password)

Your SFTP password is a private API key generated in the portal — the same place you'd create a key for the Justuno API.

1. Open the Justuno Portal.
2. Go to Account Settings → Apps.
3. Click Create private API key.
4. Copy the key. This is the password you'll enter when connecting over SFTP.

Treat this key like a password. It authenticates uploads to your account. Don't commit it to source control, share it, or expose it in screenshots. If it's ever exposed, revoke it and create a new one.

Step 3 — Prepare your suppression file

Your suppression file must follow these rules:

• Format: a .csv    or .txt    file.
• Single column only: the file must contain exactly one column of values. Files with more than one column are not supported.
• Header row: optional. You can include a header row or omit it — either is accepted.
• Values: each value should be a hashed identifier — MD5, SHA-1, or SHA-256.
• Plain email addresses: if you provide plain (unhashed) email addresses instead of hashes, Justuno will hash them to MD5 and store them internally in that form.

Examples

A file of hashed values, with a header:

email_hash
d41d8cd98f00b204e9800998ecf8427e
b1946ac92492d2347c6235b4d2611184
2c26b46b68ffc68ff99b453c1d304134
...

A file of plain email addresses, with no header (these will be converted to MD5 on ingest):

customer1@example.com
customer2@example.com
customer3@example.com

Keep a local copy of this file before uploading.

Tips and troubleshooting

• Authentication failing? Confirm your username is exactly the {domainID}    (correct domain ID pulled from embed code settings page), and that the password is a valid, active private API key (pulled from apps settings page).
• Can't see your file after uploading? That's expected — the endpoint doesn't allow browsing or downloading. Rely on your own local copy and upload log.
• Need to correct a file? Upload a new, corrected version rather than trying to edit or delete the previous one.
• Automating uploads? Store your API key in an environment variable or secrets manager rather than hard-coding it.