can a form submit with an attachment

Forms can indeed have file uploads attached.  Adding a File Upload field to your form will allow for just that.  Here is our quick guide detailing how to increase the limit as well as the maximum file sizes for different integrations:

https://www.jotform.com/help/33-Changing-the-Upload-Size-Limit

You can also change the allowed file types:

https://www.jotform.com/help/29-Upload-Field-Allowed-File-Types