Mark messages as deleted. Upon exiting with quit command these
messages will be deleted from the mailbox. Until the end of current
session the deleted messages can be referred to in message lists using
:d notation.
‘undelete [msglist]’
‘u [msglist]’
Clear delete mark from the specified messages.
‘dp [msglist]’
‘dt [msglist]’
Deletes the current message and prints the next message. If
msglist is specified, deletes all messages from the list and
prints the message, immediately following last deleted one.