Setup Email Relay To Automatically Route Email Through SMTP | Salesforce

Watch as we walk through how to set up an Email Relay. You can set up an email relay for Salesforce-generated email by configuring Salesforce to automatically route email through your company’s Simple Mail Transfer Protocol (SMTP) server.
For more information: help.salesforce.com/articleVi...
Also, review a few details before setting up Email Relay, including details about bounce management and spam.help.salesforce.com/articleVi...
NOTE: You must have Admin permission rights to perform this function.