Contact Form 7 to Email Octopus, prevent sending email

I’m trying to use a CF7 email field to subscribe users to an Email Octopus mailing list. However, it only seems to work if I set up sending of emails in CF7. I don’t want to actually send emails, I would like to JUST have them subscribed.

I could send the emails to a trashcan address, but I’d really like to be able to suppress sending of the emails at the start. Is there a way to do this?

The page I need help with: [log in to see the link]