Overview
Sometimes the Gmail spam filtering service will filter legitimate messages. Below are a few actions you or your recipients can take to ensure messages reach the Inbox.
Instructions
Add the address to your Gmail contacts
Add the email address of the person emailing you to your Gmail Contacts. Google will assign a lower spam score to a message from someone in your Contacts list.
Mark messages as ‘Not spam’
The Gmail spam filter learns over time. Marking legitimate messages as 'Not spam' helps train the filtering service. In Gmail, go to your Spam folder, select the message(s), then click Not spam above the messages.