How to Whitelist the Invoice Sender

Last updated: September 22, 2026

Clients Aren't Receiving Invoices (even though they were sent)

If you're encountering invoices that aren't reaching their intended destination even though Cartwheel has confirmed delivery, ask your client to check their spam or junk folder. You may need to ask them, or show them how to whitelist your sender address.

What is Whitelisting

Whitelisting is a pre-approved list of trusted people, items, or digital entities that are granted access, privileges, or service while everything else is blocked by default.

Whitelisting matters because legitimate emails often land in spam or junk folders when automated filters misinterpret technical authentication gaps, poor sender reputation, or unusual recipient engagement patterns as malicious activity.

What Whitelisting Means

Telling your email provider that messages from a specific address are safe, so they go to your inbox instead of spam or junk. You only need to do this once.

In many organizations, this filtering is set organization-wide by your IT team.

Share the address/s to add

Share the email address you use to send invoices from Cartwheel with your clients. If you have not whitelabeled, that address is <no-reply@email.cartwheel.io>. If you have whitelabeled your sender domain, it will be different.

↗ Click Here For an Article & Instructions on Whitelisting You Can Share With Your Clients

Not sure which email provider your clients use? If they log in to email at mail.google.com or they use Google Workspace, have them follow the Gmail steps. If they use the Outlook app, outlook.com, Teams, or Microsoft 365, follow the Outlook steps. When in doubt, ask your IT team.

Gmail (individual users)

Option A: Create a filter (recommended)

  1. Open Gmail on a computer (these settings aren't available in the mobile app).

  2. Click the gear icon in the top right, then click See all settings.

  3. Open the Filters and Blocked Addresses tab.

  4. Click Create a new filter.

  5. In the From field, enter [Cartwheel sender address], then click Create filter.

  6. Check the box for Never send it to Spam, then click Create filter.

📷 See it with screenshots: Google Help: Create rules to filter your emails

Option B: Add to contacts

  1. Open any email from [Cartwheel sender address].

  2. Hover over the sender's name and click Add to contacts.

If an email already landed in Spam: Open your Spam folder (click More on the left if you don't see it), open the email, and click Not spam at the top.

📷 See it with screenshots: Google Help: Mark or unmark spam in Gmail

Outlook (new Outlook for Windows, Outlook on the web, Outlook.com)

  1. Click the gear icon (Settings) in the top right.

  2. Go to Mail > Junk email.

  3. Scroll down to Senders and select the Safe senders and domains tab.

  4. Click + Add safe sender and enter [Cartwheel sender address].

  5. Click OK, then Save.

Outlook (classic desktop app for Windows)

  1. On the Home tab, click Junk > Junk E-mail Options.

  2. Open the Safe Senders tab and click Add.

  3. Enter [Cartwheel sender address] and click OK, then OK again.

If an email already landed in Junk: Right-click it and choose Mark as not junk (or open it and click Not junk).

📷 See it with screenshots (all Outlook versions): Microsoft Support: Add recipients to the Safe Senders List in Outlook. Pick your version (New Outlook, Classic Outlook, or Web) from the tabs near the top of the page. Personal Outlook.com users can also use Safe Senders in Outlook.com.

Apple Mail, Yahoo, and other providers

Add [Cartwheel sender address] to your contacts. If a message lands in spam or junk, mark it as "Not spam."

For IT administrators (company-wide)

If the organization filters email centrally, a user-level safe senders list may not be enough. Your client may need to ask their IT team to allow the sender address or domain at the organization level:

  • Google Workspace: In the Admin console, go to Apps > Google Workspace > Gmail > Spam, Phishing and Malware. Under Spam, add a rule that bypasses spam filters for an approved sender list containing the address or domain. 📷 Google Workspace Admin Help: Customize spam filter settings

  • Microsoft 365: In the Microsoft Defender portal, go to Email & collaboration > Policies & rules > Threat policies > Tenant Allow/Block Lists, and add an allow entry for the address or domain. 📷 Microsoft Learn: Allow or block email using the Tenant Allow/Block List

  • Third-party email security (e.g., Mimecast, Proofpoint): Add the address to the permitted senders policy per your vendor's documentation.