Aid4Mail cannot read or write OST files natively. Aid4Mail can only process an OST file if it's connected to a MAPI profile (Outlook or Exchange account).
In this case, you'd need to use the "Email profile" option on Aid4Mail's Target Format or Mail Source screen.
If you experience any issues, don't hesitate to contact us.
If you would like to buy an Aid4Mail license, visit the Aid4Mail website.