There’s no getting it back – except for some exceptional circumstances I’ll talk about in a moment.Desktop email programs store email on your computer in a variety of different ways.When it comes to online services, we really don’t know how trash is handled.All of that is hidden behind the service provider’s interface.Where the email program keeps individual messages as individual files, it’s pretty safe to assume that these behave exactly like deleted files, because they PST is an acronym for Personal STore, and is the file format used by the Microsoft Office Outlook email and personal information management program.In addition to email, PST files contain calendar, contacts, notes, journal and other information that is used and manipulated by Outlook.Some use a fairly complex database all kept in a single file, some use a slightly less complex separate database file for each folder, and others actually use your operating system’s disk structure, mapping email folders to disk folders and storing individual email messages as individual files.
Microsoft provides the utility “scanpst” to scan and repair PST files suspected to have issues. Much like a disk, when a message it deleted it’s simply marked as deleted, but not actually overwritten until the space it was using is needed.
The complication is that the compact function may itself operate by the old one.
That in turn means that there may be a deleted copy of the old database that could be undeleted, which could still contain remnants of the deleted message. One thing that’s very easy to overlook is the impact of backing up when it comes to retrieving email.
The advantage of the PST is that it is a single file; all information can be copied to another machine or backed up simply by operating on that single file.
The disadvantage of the PST is that it is a proprietary file format readable only by Outlook.