DELETE  -  mark the current message for deletion

Usage:  DELETE  

DELETE marks the message as deleted.  The message is not removed from 
  the file until you use the commands EXIT, EXPUNGE or BYE.

To READ a deleted message, use the TYPE command in READ MODE, or UNDELETE 
  it and then read it. 

For more help, type "help" and one of these topics:
   kill   type   undelete   message-handling
   top-level-mode exit   top-level-mode expunge

