Luckily, there’s a good chance you can recover your mistakenly deleted item if you’re using Microsoft Exchange Server as your mail server. (If you’re not, and you’re using a web-based mail address like Gmail or Yahoo! mail, your best option is to log into the web interface for your email and search there.)
Select the Deleted Items and look at the top of the folder pane for the “Recover items recently removed from this folder” option.
All these options launch the same Recover Deleted Items tool, which displays a list of items in the Recoverable Items folder.
You can also purge emails from here as well. Select items you want to delete permanently, switch “Purge Selected Items” on, and then click “OK.”
This is a serious warning-purging an item deletes it from Exchange, and it’s gone forever. There’s usually no reason to purge your email, so if you’re in any doubt, don’t use the Purge option.
If you’ve deleted something accidentally, and you can’t find it using the Recover Deleted Items tool, do nothing else and call your tech support team immediately. They might have tools that can get your email back, but be warned: they might not. So don’t forget to back up regularly!