Mail

See this article https://support.apple.com/kb/PH2646?locale=en_US&viewlocale=en_US

Move messages into a folder

Do either of the following:

• Select the message or messages, then drag them to a folder.
• 
  
• Select the message or messages, click the Move to Folder button, then choose a folder.

Note : if the mails are in the trash folder and they are not deleted permanently , you can select the mails once again and move them to inbox folder , make sure do this before 30 days after the 30 day time period they are permanently erased from the iCloud server .

What do you mean “recover” them? If you deleted them and then emptied the trash folder, they are gone for good. Otherwise, they should be in one of your iCloud mail account folders.