How to setup org-wide HR address for notifications

From Setup, enter Organization in the Quick Find box, then select Organization-Wide Addresses

Click Add

Define fields with Display Name and Email Address

Choose Allow All Profiles to Use this From Address

Click Save

We've just added email, which allowed for all profiles

Now we need to verify this email. We are going to email the account and clicking on the verification link

Then click Continue

From Setup, enter Custom Settings in the Quick Find box, then select Employee Notification Settings

Then click Manage

Click the first New button

Then enter your org-wide email address defined above

Click Save and that is all! All your notifications will come from your new HR email address.