If you are looking for a reliable OST to PST tool, EdbMails OST to PST Converter is one option worth considering. It can convert OST files to PST while retaining emails, folders, attachments, contacts, calendars, and other mailbox data.
One useful feature is that it supports unlimited OST to PST conversion without a file-size limit, which can be helpful when working with large OST files. It also provides a free trial to evaluate the conversion before purchasing.
For users comparing the top 10 OST to PST tools, EdbMails is worth including based on its conversion features, pricing, free upgrades, and 24/7 technical support.