Apple "Mail" program delete command doesn't work on messages in trash

Trying to get my script to delete all emails in all folders whose name contains ‘trash’, ‘delete’, or junk.
It will move files in junk folder into trash, but won’t delete trash

use AppleScript version "2.4" -- Yosemite (10.10) or later
use scripting additions

tell application "Mail"
	set accountsList to name of accounts
	repeat with anAccount in accountsList
		set anAccount to contents of anAccount --mailboxes of account anAccount --mailbox "Junk" of account anAccount
		set mailboxList to mailboxes of account anAccount
		set c to 1
		repeat with i from 1 to count mailboxList
			set flag to true
			repeat with mboxName in {"deleted", "trash", "junk"}
				if mboxName is in name of item i of mailboxList then
					set flag to false
					exit repeat
				end if
			end repeat
			if flag then
				set item i of mailboxList to item c of mailboxList
				set c to c + 1
			end if
		end repeat
		set mailboxList to items c thru -1 of mailboxList
		repeat with aMailBox in mailboxList
			set deleteList to messages of aMailBox
			repeat with aMsg in deleteList
				set aMsg to contents of aMsg
				delete aMsg -- won't delete message if already in trash folder
			end repeat
		end repeat
	end repeat
end tell

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