If you'd like to screen emails from senders that are not in your contacts, you can create a mail rule to filter these emails into a different folder. You can then look through those emails and decide what actions to take on them.
Follow the steps below to set this up:
- Go to the Settings → Folders screen.
- Click Create folder to create a folder (or Create label if you are using labels). You can name it "Screen Emails" or something similar.
- Go to the Settings → Mail rules screen.
- Click Create rule.
- For the first condition of the rule, click the button that says "From." From the dropdown menu, select the option Sender is not a contact.
- Click Continue. This will take you to the mailbox screen and show a preview of the emails matching the condition.
- Click Create rule. In the pop-up that appears, choose the Move to option and select the "Screen Emails" folder you created.
- Be sure to click Save.
Once this has been done, emails from any sender that is not in your contacts will be automatically moved to your "Screen Emails" folder. You can check this folder and decide what actions you would like to take on the messages or senders. If you want to approve any senders, you can do so by adding them to your contacts.