In Blackboard it is recommended that you have your students submit their work using any of the following file formats; Word (DOC, DOCX), PowerPoint (PPT, PPTX), Excel (XLS, XLSX), and PDF (PDF). If students submit RTF files you are required to download each assignment manually grade their work and send the file back to your students via email or another source.
If you change your instructions and tell your students to submit their work using the above file formats no download is required. Blackboard has inline grading using Box features built into the system. Faculty have the ability to grade, markup, and provide feedback to students from within Blackboard. Here is a video on how to grade submitted assignments using the Inline grading feature. I have also included the directions for students (below) on how to upload a file and what format they need to use. This can be copied and pasted into your assignment. If you have any questions please let me know.