Did you look at this TID as it has 2 settings for windows itself that we have seen improving the speed a lot. 

Other questions would be:

Also all workstations or some have this

All users or some have this

All email or some have this

This to see if this is workstation/user or mail related and if there is a case to test provide a EML that show the issue on your system but also test if other workstations have the same with this email.

Hi Rob

Yes, NetBios is deactivated, already

Several users report this (myself too), this from different Dom/PO, Worksations/Server. And yes, several mails with inline images, in case some rendering is needed. If in cache mode, where client does rendering, there is no problem ...

EML has uploaded to FTS , case 02865796 , you should have access ;-)

Thanks and regards

Markus

Hi Markus.

I see that you struggling with the similar issue that we have too. Did you get any solution regarding GW client slowness? We have the same problems with exactly same version.

Does anyone has any idea how to troubleshooting this?

Really appreciate for any feedback.

Grega

Hi Gregor

I mean, the solution was to update and then archive, unarchive affected emails.

regards

Markus