I've made some tests with the plugin - which is brilliant, by the way. A user sent a txt file as an attachment. No notification that the file was not attached, and I didn't receive anything. Once the user tried with a png file, I received the attached image. I don't mind attaching only images, I wouldn't mind to have the option to remove the "attach file" button. But, can you tell me how can I modify or add the text that users should only upload images?
Something like: "Attachments - only png, jpg files allowed)
The way the plugin works now they could try to upload anything, since they don't know I'm not receiving the attached files. On the other side, I wouldn't know that they tried to attach files. Or I'm doing something wrong...?