Defrtag should be disabled but Windows should do that for you. The rest should be left alone, these modern drives last decades with no special effort made to reduce writes.
When I say Windows will turn defrag off, what I mean is it will remove the SSD from the scheduler. It won't actually disable defrag in case you want to defrag mechnical drives.
Indexing is now considered beneficial. It will speed file searches and if you have Outlook it will greatly speed email searches (and possibly in other email clients?)
Prefetching doesn't make much noticeable different either way as far as I can tell.
Just to add, you are correct Targetbsp, if you disable that it does also affect other email clients. I use windows love mail desktop, and with search or indexing disabled you cannot search through your emails - except by title which is terrible!
So having it enabled not only speeds up email searches, it also allows the search to look through the actual email not just the title.
