Hello,
Here are some findings, the problem isn’t coming from the fact that I use Box plugin, I think something changed somehow, when I attach to an email a unique file, the attachment is OK, when I have more than one file, the emails goes with no attachment.

I’m sure it was working before, I tried an empty page with only a Multi File Uploader and a button to send an email and I have the same results.

So my question is, how should the file list look like in the attachment field of the action Send Email ?