Outlook VERY slow on netClient

SBS Server edition and adnm netClients deployed.

When opening outlook with preview/reading pane on, scanning of new emails can take upto 5 seconds to refresh the reading pane.
I had this same problem on the avastpro version but I turned off “scan body” so only attachments were scanned and this helped but obviously not an ideal solution.

Anyone had / resolved this or any ideas?

Many thanks in advance.

Bump. Nobody else got this problem?