You and your customers can upload attachments into your Re:amaze conversations using the simple drag and drop section beneath your conversation reply o by clicking on the paperclip icon on the customer side.
The file size limit on Re:amaze's end is 100MB so you can upload and send big files as long as your customer can receive them. If you wish to attach a picture or file in line, simply use markdown to link the picture or file. Make sure the file or image is hosted elsewhere in this case.
Re:amaze supports most file formats ranging from documents to PDFs and from Photoshop files to spreadheets.