I stopped receiving emails and seem to have accidentally deleted everything in my Thunderbird inbox.

Repairing only re-indexes what Thunderbird has, or in the case of IMAP checks for the latest versions on the server and deletes everything pending the new downloads. SO, I am guessing you are having connectivity issues that have extended far further than you anticipate. What exactly is this timeout issue? DO you have an antivirus scanning mail? Disable mail scanning as a first move to see if that is the cause of the timeouts. (it often is) and clean up the system temp folder (that can cause the system to slow to the point of timeouts. General instructions follow. # Press Win + I to open Settings. # Click on System, then select Storage on the left menu. # Click on Temporary files under your main drive (usually C:). # Wait for Windows to finish scanning your system. # Check the boxes next to the temporary items you want to remove (such as Temporary files, Recycle Bin, or Windows Update Cleanup). # Click Remove files.