my attachments aren't sent in cf7

Hello,

I am setting up some forms using his plugin, and almost everything works as I expect. Except for 1 problem:

I want to send 2 pdfs to the person filling out the form. So in the attachment field of email2 I have added the absolute paths to the 2 files (both on a new line).
The mails are sent, but the mail contains no attachments.
I have checked the paths and they are valid.

I would really like to send them with the mail, instead of asking people to download them. And it looks like it should be possible.
So there is either a bug, or (more likely) I am forgetting to do something…

Your help is appreciated!

thanks
Joke

https://wordpress.org/plugins/contact-form-7/