Known External Senders
Mark trusted business partners and vendors as "Known External" so users see blue banners instead of gray on their authenticated emails.
Written By Matt Sywulak
Last updated 2 months ago
Admin Center > Analysis > Known External Senders
Add Trusted Senders
Enter comma-separated list of:
Email addresses -
partner@vendor.comFull domains -
vendor.com(includes subdomains)Specific subdomains -
mail.vendor.com
Example: acme.com, vendor.com, partner@supplier.net
Key Points
Authentication required - Senders must pass SPF/DKIM/DMARC. Unauthenticated mail won't get Known External label even if listed.
Team domains automatic - Don't add your own domains here. Authenticated mail from team domains gets Known External automatically.
Blue banner effect - Users see these senders are verified external contacts, reducing security fatigue on legitimate business mail.
Typosquatting protection - Domains listed here (including subdomains) get direct typosquatting detection. INKY will flag lookalike domains targeting these trusted senders instead of relying on automatic detection.
When to Use
Add frequent business partners, vendors, or service providers where you want to signal trust to users. Avoid adding unknown senders just because they seem legitimate—let INKY's detection handle those.