Approval Process Email Notifications Not Received by Some Users

Remove inactive Users from an Approval Process

1. Navigate to Setup | Create | Workflow & Approvals | Approval Processes
2. Select an object for "Manage Approval Processes For:"
3. Click the Approval Process Name.
4. Under Approval Steps, click Edit on the first step. This can be identified by "1" in the Step Number column.
5. Click Next until you are at Step 3, remove the inactive users.
6. Click Save.

1. Navigate to gear icon | Setup | Process Automation | Approval Processes
2. Select an object for "Manage Approval Processes For:"
3. Click the Approval Process Name.
4. Under Approval Steps, click Edit on the first step. This can be identified by "1" in the Step Number column.
5. Click Next until you are at Step 3, remove the inactive users.
6. Click Save.

Note: This can also happen if the User record of the affected user has the "Receive Approval Request Emails" field set to "Never." To check, go to:
 

In Salesforce Classic: Setup | Manage Users | Users
In Lightning Experience: gear icon | Setup | Users | Users
 

1. Click Edit beside the name of the affected user.
2. Make sure the "Receive Approval Request Emails" field is not set to "Never."
3. Save.