Slow on sync

When I click on new email takes approx. 6 seconds before its shows as read. In Thunderbird for example its instant.

Check Menu - Extras - Configuration - Email - Read - read, there you can set the “mark as read after x seconds”, or similar, i only know the german GUI. 3 seconds is fine for me, i don’t want it to be instantly marked as read before i even had the chance to read it.