Ah yes, the server - if it is anything like my computer in 2011 that is the solution. I am thinking of making my pc commit hari kiri (sorry if spelling is wrong) as it is certainly driving me up the wall. My work mouse has been filed in the circular file already this year and the rest will soon follow ... watch this space!
Who knows the missing message will probably turn up somewhere! Could everyone turn out their pockets, just in case ...