Outlook - Email Flood

An email flood is when you receive a wave of unwanted emails. You can use rules to divert unwanted emails or block senders.

An email flood is when you receive a wave of unwanted emails. You can use rules to divert unwanted emails or block senders. If the email flood is part of a continued campaign of targeted spam emails, review the knowledge base article Electronic Harassment.

Block a sender

You can automatically filter the emails to the Junk folder. Emails in your Junk folder are permanently deleted on a regular schedule.

  1. In Outlook, right click on the email
  2. Click Block > Block sender

Create an email rule

Instead of blocking a domain entirely, you can use rules to filter emails into a separate folder. This approach is best if you're uncertain about the email's origin and don't want to accidentally block a valid sender.

  1. In Outlook, click the Settings (gear icon) > Mail > Rules
  2. Click + Add new rule
  3. Name your rule: (e.g., "Sort Work Emails")
  4. Add a condition: Select Keywords from the dropdown
  5. Choose Sender address includes
  6. Type the domain (e.g., @companyname.com)
    • You can add multiple domains. Press Tab after each email domain
  7. Select Move to and choose your desired folder, or click Create new folder
  8. Optional: Check "Run rule now" if you want it to organize your existing inbox immediately
    • Processing time may vary depending on your inbox size, but you can continue working while the rule runs in the background.
  9. Click Save
  10. Optional: Create a retention policy
    • Right click on the folder > Assign policy > Select a time frame

Unsubscribe from email lists

Warning: Only click unsubscribe links if you are certain the sender is legitimate. Unsubscribing from a spam email will alert the spammer that your account is active and in use. Clicking any malicious links can lead to more emails and potential cybersecurity risks. If you're unsure, please contact Technical Support.

If you are receiving emails from a verified website, you can unsubscribe from them.

  • Modify your subscription preferences on the verified website
  • Look for unsubscribe directions in the footer of the email

If you accidentally clicked on a malicious link or have cybersecurity concerns, please contact Technical Support.

Also see: Microsoft 365 - Report Suspicious message



Keywords:
emails bomb spam phishing junk hack mail security 
Doc ID:
160995
Owned by:
Brianna M. in L&S ITS - Technical Support
Created:
2026-04-28
Updated:
2026-05-08
Sites:
L&S ITS - Technical Support