It makes no difference which Outlook version you are using. Basically, recovering lost OST files doesnt depend on the existing version of your Outlook. However, here are some effective ways for recovering a deleted OST file in Outlook 2016:

1) Use shadow copies 

Windows has a built-in feature called Shadow Copies, which creates snapshots of your files at various points in time. If you have this feature enabled, you may be able to recover a deleted OST file by restoring a previous version of it. To do this: 

• Right-click on the folder where the OST file was located and select "Properties."

• Then, click on the "Previous Versions" tab and look for a version of the folder that contains the deleted OST file.

• If you find one, select it and click "Restore."

2) Check your cloud backup. 

If you use a cloud backup service like OneDrive, Dropbox, or Google Drive, you may be able to recover a deleted OST file from your cloud backup. Check your backup service's website for instructions on how to do this.

3) Contact Microsoft Support 

If none of the above methods work, you may need to contact Microsoft Support for assistance. They may be able to help you recover the deleted OST file or suggest other methods to try.

4) Use a professional Regain OST Recovery tool 

There are several third-party recovery tools available that are specifically designed to recover OST files in Outlook. These tools can scan your computer's hard drive for deleted OST files and recover them. 

Keep in mind that the effectiveness of these methods may vary depending on your specific situation. It's a good idea to try multiple methods to increase your chances of recovering the deleted OST file.