In order to fix a problem with the way in which Skype for Business works with Outlook, ITS will need to restart all exchange servers tomorrow – Thursday 30th July.
Hopefully most of us will not notice anything but you may find for a short period between 9:15 and 10:00 that outlook is not responsive (e.g. for looking up contacts; sent email sitting in the outbox, etc. ) As soon as the server restarts all this should come right.
If you are connecting via a Web Browser to any mailbox, then you will probably be prompted to login again.