Gmail offers an option to add specific addresses or domains as "safe" so they aren't automatically marked as spam. This list is known as a "Whitelist." Your Whitelists only apply to your Gmail account, and must be managed and set by you. If you want to accept all email sent from a specific address, follow these instructions:

  1. Log in to your Gmail at gmail.com. 
  2. Click the gear icon in the top-right, and select Settings.
  3. Click the Filters and Blocked Addresses tab. 
  4. Click Create at New Filter. 
  5. In the pop-up window, enter the email address you want whitelisted in the From field.
    • If you want a whole domain whitelisted, you can just enter the domain (ie, "@example.com").
  6. Click Create filter.
  7. Check "Never send it to Spam".
  8. Click Create filter.