I have several castles with different email addresses, I deleted the wrong ones by mistake can I retrieve..

You will need to know the email addresses to log in again (assume they are bound to IM30 accounts). with the email address you can reset the password.

If you don't have these then the only option is to use the Retrieve Lost account option in the game (Settings => Account, link at the bottom). This will let you send your info to the game support and they may be able to help you get them back.