class Net::IMAP

def copy(set, mailbox)

the moved messages.
mailbox, the UID set of the source messages, and the assigned UID set of
with UIDPlusData. This will report the UIDVALIDITY of the destination
supported, the server's response should include a +COPYUID+ response code
If +UIDPLUS+ [RFC4315[https://www.rfc-editor.org/rfc/rfc4315.html]] is

===== Capabilities

Related: #uid_copy

Range object. The number is a message sequence number.
+mailbox+. The +set+ parameter is a number, an array of numbers, or a
to copy the specified message(s) to the end of the specified destination
Sends a {COPY command [IMAP4rev1 ยง6.4.7]}[https://www.rfc-editor.org/rfc/rfc3501#section-6.4.7] 
def copy(set, mailbox)
  copy_internal("COPY", set, mailbox)
end