You can download AfterLogic WebMail Pro PHP 4.8.15 at:
http://www.afterlogic.com/download/webmail-pro-php.zip

1. If you are using WebMail Pro 4.5 or any older version, contact us for upgrading your license key (it's free for registered users). Please specify your e-mail address you used to purchase the product or your order number. This will allow us to locate your order and send you the correct license key.

2. Move your existing WebMail Pro installation to any backup location, including the data folder. Back up WebMail Pro database as well.

3. Extract all the files and folders from the downloaded archive to your WebMail Pro installation location. If you have the data folder placed outside of the web folder, place the data folder from the archive to that location.

4. Restore the following files and folders from the backup location to WebMail Pro installation:

in the web folder:

• inc_settings_path.php

in data folder:

• settings/settings.xml
• settings/adminpanel.xml
• Mail folder

5. Navigate to WebMail Pro Admin Panel:

http://<WEBMAIL-PRO-ON-YOUR-SERVER>/adminpanel

6. If you've received new license key according to step 1, navigate to License Key section, replace the license key and click Save.

7. WebMail Pro should get all the settings from the previous WebMail Pro installation, you just need to update WebMail Pro database format by clicking "Update" button in Database Settings screen.

8. Once logged into WebMail Pro itself, don't forget to press Ctrl+F5 or Ctrl+R to update web browser cache to avoid JavaScript errors.