Same mail with different mail ids in mail.app when running Apple Scripts from DEVONthink 3

Sure.

-- Import attachments of selected messages to DEVONthink.
-- Created by Christian Grunenberg on Fri May 18 2012.
-- Copyright (c) 2012-2020. All rights reserved.

tell application "Mail"
	try
		tell application id "DNtp"
			if not (exists current database) then error "No database is in use."
		end tell
		
		set theSelection to the selection
		set theFolder to (POSIX path of (path to temporary items))
		
		if the length of theSelection is less than 1 then error "One or more messages must be selected."
		
		repeat with theMessage in theSelection
			set theSender to the sender of theMessage
			repeat with theAttachment in mail attachments of theMessage
				-- try
				if downloaded of theAttachment and (name of theAttachment ends with ".pdf") then
					set theFile to theFolder & (name of theAttachment)
					tell theAttachment to save in theFile
					tell application id "DNtp"
						set theAttachmentRecord to import theFile
						set URL of theAttachmentRecord to theSender
						perform smart rule trigger import event record theAttachmentRecord
					end tell
				end if
				-- end try
			end repeat
		end repeat
	on error error_message number error_number
		if error_number is not -128 then display alert "Mail" message error_message as warning
	end try
end tell