A trusted sender is a sender who only sends email to those recipients who have given them express permission to do so.
A trusted sender (some services use the term, "white hat sender") is a sender or company who only sends email to those recipients who have given express permission to receive email from the sender. Put simply, trusted senders always strive to “send the right message, to the right person, at the right time, with the right frequency.”
SendGrid has a plethora of resources to help you be a trusted sender, and to get your email to the inbox and not the spam folder. Check out our email deliverability tips to help.