- Login to SmarterMail with admin user.
- Click on Settings icon and select System Administrators option from the left pane.

- Select administrator user you wish to edit, then click on Edit.

- Check the checkbox Enable Login Access by IP Address. This will enable Login Access tab.

- Click on Login Access tab and select Add option from the actions toolbar.
- Type an IP address or range of IP addresses then click on Save button.

- Click on Save.
It's a good idea to restrict SmarterMail admin login only from specific (in house) IP address. Following are the steps you should follow to accomplish this.