To help prevent spam and malicious email, add individual email addresses or entire domains to a blocked senders list. This way, you’re automatically rejecting messages from them.
Kindly follow the steps as mentioned below:
- In your Google Admin console(at admin.google.com)...
To apply the setting to everyone, leave the top organizational unit selected. Otherwise, select a child organizational unit.
Point to Blocked senders and choose an option:
To edit an existing setting, click Edit.
For a new setting, click Configure or Add anotherenter a unique description.
Click Use existing.
- To use an existing list as your blocked sender list, under Available lists, click the list name.
Enter one or more IPs. Separate each entry with a comma or space.
- Click Add Setting or Save.
The Gmail Advanced settings page will display new settings.
- At the bottom of the page, click Save.
- It can take up to 24 hours for changes to take effect. You can track changes in the Admin audit log.
Note: Be sure to enter public IP4 addresses as private IPs are not accepted. Also, IP4 IP Addresses should be in proper format.