alex786:
Do you have large size PST file or want to reduce the size of the PST file? If yes, then I would suggest you go with PST Duplicate Remover. The tool will help you to remove all duplicate emails or items from the PST files without any changes or edit in the original data. You can remove duplication items from any version of Outlook PST files. I would also recommend you to try a trial version of this Outlook PST Duplicate Remover. With the help of the trial version, you can remove the first fifty items per PST file.
davidgodfin:
There are different ways to deal with large PSTs. For example, split and archive a large PST file. You can also remove unnecessary items like duplicates, but more important would be to remove duplicate attachments from emails or replace them with links, using these free tools: https://www.outlookfreeware.com/en/products/all/OutlookAttachmentsRemoveDuplicates https://www.outlookfreeware.com/en/products/all/OutlookAttachmentsReplace