Block email sender office 365 admin

As an Office 365 admin, you can block an email sender using the Office 365 admin center or PowerShell. Here are the steps:

Method 1: Using the Office 365 Admin Center

1. Sign in to the Office 365 admin center with your admin credentials.
2. Go to Protection > Anti-spam > Junk email.
3. Click on Block senders.
4. Enter the email address or domain of the sender you want to block in the Block sender field.
5. Click Add to add the sender to the block list.

Method 2: Using PowerShell

1. Open PowerShell as an administrator.
2. Connect to your Office 365 tenant using the following command: Connect-ExchangeOnline -UserPrincipalName <your_admin_username> -ShowProgress $true
3. Run the following command to block an email sender: Set-ThrottlingPolicy -Identity <policy_name> -BlockedSenders <sender_email_address>
   • Replace <policy_name> with the name of the throttling policy you want to use (e.g., "Default").
   • Replace <sender_email_address> with the email address of the sender you want to block.
4. Run the following command to verify that the sender has been blocked: Get-ThrottlingPolicy -Identity <policy_name> | fl BlockedSenders

Note: When you block an email sender, all emails from that sender will be rejected and not delivered to your organization.

Additional Tips:

• You can also use the Office 365 admin center to create a custom spam policy that blocks specific senders or domains.
• If you want to block a domain instead of a specific sender, you can use the Set-ThrottlingPolicy cmdlet with the -BlockedDomains parameter.
• You can also use the Get-ThrottlingPolicy cmdlet to retrieve a list of blocked senders and domains for a specific policy.