Here's the basic steps to manage spam emails for gmail.
How to set Gmail Spam Filter:
- Log in to your Gmail account.
- Click the GEAR icon at the top right and then click SETTINGS.
- Go to FILTERS AND BLOCKED ADDRESSES and click CREATE A NEW FILTER.
- In the FROM section, type the email address of the sender that you want to keep out of your Spam Folder.
- Click CREATE FILTER.
- Check NEVER SEND IT TO SPAM and ALSO APPLY FILTER TO MATCHING MESSAGES boxes.
- Click CREATE FILTER again.
For organisation level, GSuite Administrator has the ability to do so.