Under General Options-->Synchronization Reports-->Log, currently we have options: All, Errors, or Errors+Warnings. A very handy option would be "Only sync runs with changes."
I find it useful to be able to look back & verify a history of changes, thus I have it set on "all" - but there are many entries where it's just checking the server with no change.
Ticket moved from /p/outlookcaldavsynchronizer/tickets/1137/