Microsoft 365 allow-list
Outlook whitelist-only mode for approved senders.
KeepKnown gives Outlook and Microsoft 365 users contact-based routing for non-approved senders without permanent blocking.
Outlook whitelist-only mode is useful when unwanted mail is legitimate enough to pass spam filtering but still should not interrupt executives, founders, or security-sensitive teams. KeepKnown uses contact-based routing to keep approved senders visible and move non-approved senders into a recoverable review area.
Short answer
Outlook rules help, but contact-based allow-listing is stricter.
Use Outlook and Microsoft 365 rules for known patterns. Use KeepKnown when the inbox should prioritize approved senders and route everyone else away from the main inbox without deleting mail.
Spam filters decide what looks bad. Allow-lists decide who is allowed.
Executive inboxes
Keep vendor pitches, cold outreach, and unfamiliar senders away from the main inbox while approved contacts stay visible.
Microsoft 365 teams
Add a relationship-based layer beside Outlook rules and Microsoft 365 security controls.
Recoverable review
Unknown mail is routed aside, not deleted. If a new sender matters, approve them and continue.
A stricter Outlook inbox without permanent blocking.
Connect Outlook
Authorize KeepKnown with Microsoft so it can apply contact-based screening.
Confirm trusted senders
Use contacts and VIP domains as the allow-list for people who should reach the inbox.
Screen everyone else
Route unfamiliar senders away from the inbox so Outlook stays focused on approved mail.
Questions before you connect.
Can Outlook run in whitelist-only mode?
Outlook and Microsoft 365 can use rules and safe senders, but KeepKnown adds recoverable contact-based routing for non-approved senders.
Does KeepKnown support Outlook and Microsoft 365?
Yes. KeepKnown supports Outlook and Microsoft 365 inboxes connected with Microsoft authorization.
What happens to non-approved Outlook senders?
They are routed away from the main inbox for review instead of being permanently blocked or deleted.
Is this the same as a spam filter?
No. Spam filters judge message risk. Contact-based allow-listing checks whether the sender is trusted.
Related inbox workflows
Outlook allow-list
Route non-approved senders without permanent blocking.