Classic Outlook caps the list at roughly or a total file size of 512 KB. Domain Blocking
. A moment later, his inbox chimed. Seventeen "URGENT" follow-ups from Martha flooded in at once. Arthur sighed, looked at his pristine mahogany desk, and realized that sometimes, the only thing worse than a blocked sender is an unblocked one. AI can make mistakes, so double-check responses Copy Creating a public link... You can now share this thread with others Good response Bad response 11 sites Block or unblock senders in Outlook - Microsoft Support Add unwanted names to the Blocked Senders List. Messages from addresses or domain names in the Blocked Senders List are always tre... Microsoft Support Block or unblock senders in Outlook - Microsoft Support Add unwanted names to the Blocked Senders List. Messages from addresses or domain names in the Blocked Senders List are always tre... Microsoft Support Block or unblock senders in Outlook - Microsoft Support To add a specific sender to the Blocked Senders List, click a message from the sender. On the Home tab, in the Delete group, click... Microsoft Support can't find "blocked senders" in MS Outlook - Microsoft Q&A Nov 10, 2025 —
Blocking domain.com does not automatically block subdomains like domain.com . list of blocked senders in outlook
Create a new rule stating: "If the sender's address contains [keyword/domain]" . Set the action to: "Delete it" or "Permanently delete it" .
Understanding the Blocked Senders List in Outlook The in Microsoft Outlook is a built-in security feature designed to block unwanted emails. When you add an email address or an entire domain to this list, Outlook automatically routes matching incoming messages directly to your Junk Email folder. This prevents spam, phishing attempts, and unwanted newsletters from cluttering your primary Inbox. How to Find and Manage the Blocked Senders List Classic Outlook caps the list at roughly or
Emily started to scroll through her inbox, looking for spam emails to add to the Blocked Senders list. She found a few messages from senders that she knew were spam, and she added them to the list.
By adding these senders to her Blocked Senders list, Emily was able to prevent them from sending her emails in the future. She had taken a proactive approach to managing her inbox, and it had paid off in a big way. Seventeen "URGENT" follow-ups from Martha flooded in at once
Here are some best practices for using blocked senders in Outlook:
Excited by this discovery, Emily opened her Outlook account and navigated to the "Junk Email" settings. She clicked on the "Blocked Senders" tab and saw that it was empty.