Forward spam mail out of the list (unopened)

Hello everybody.
I used to forward spam mail unopened from the list of received mail to an anti-spam service
As this does not work anymore with the new version of K-9 and I fear to open such mails I’m not sure how to proceed.
(I posted my question on ‘General’ because the following three search terms didn’t have any matches: spam, forward, security)
Can You please help?
Thank You so much!