Attachment appearing in notification email

Hello,
This plugin seems to be working flawlessly and has brought some great and much needed features to my site. I have one issue however, it seems that the “Attachment: document.docx” is somehow making its way onto a notification email we have set up to inform the original post author that a comment has been added.

This is by no means a huge problem, but I don’t know why it is appearing. The plugin we are using for the notification is ‘Custom Comment Notifications’; this has allowed us to add html styling to the email notification. Everything appears in order except for the attachment information is showing up un-styled at the bottom of the page.

Any ideas on how to remove this? or control it?

Thanks.

https://wordpress.org/plugins/comment-attachment/