How to whitelist email in Gmail
There are two ways to do this in Gmail—by adding the email sender as a contact and by creating a filter.
Add sender to contacts
1. Open the email and click the Contacts icon on the right-hand side.
2. Select the sender and then click the Add to contacts icon at the top.
And that’s it!
Create a whitelist filter
1. In your inbox, click the Settings icon in the top right corner, then click See all settings.
2. Navigate to the Filters and Blocked Addresses tab and select Create a new filter.
3. Simply add the email address you would like to allow in the From field and click Create filter.
4. Select Never send it to Spam and (optionally) Always mark it as important. Click Create filter one last time and the email address will be added to your whitelist!