Hi

I am having the same problem with a mailbox that is shared between several users. Any attachment from the shared mailbox is taking over 30 seconds to open.

This is an exchange mailbox that is added to each end-users outlook profile as an "additional mailbox"

If i create a new outlook profile with this shared mailbox this will obviously create a new .ost with this mailbox as the primary. ALL attachments open instantly from this outlook profile

Is there any way to speed up the performance of opening attachment (and emails) when the mailbox is used as an "additional mailbox'?

Appreciate your assistance in advance