Draft email disappeared after I had saved it!

Hi, Hopefully someone can help. Last night I was typing an important draft email, I kept saving it as I was going along even though I noticed outlook was automatically saving it every so often. Before I signed out I ensured I saved it and noted the interface said last saved at 10:45pm. After logging out I remembered something else I wanted to add to the draft but once I opened it I realised it was the version from much earlier in the evening. I have checked all of my other folders to find the draft but to no success. Does anyone know how I can recover it? Thanks