@Marcos, this Outlook-Addin discussion is more than annoying.
Being a ESET Gold Partner for almost 10 years I trust a lot into ESET’s product quality. But the Outlook addin has a general design flaw. It is tracking mails that have been scanned by changing a mail attribute. As soon as you have shared mailboxes that are being accessed from more than one Outlook user in cached mode, this will cause massive conflicts.
The only solution for this problem is to stop changing mail content or attributes. This should be the default setting, since O365 with cached mode and shared mailboxes is the default in today’s businesses around the world.
We have these issues at each and every customer.
Can you please let us know when this issue will be finally resolved in the default configuration.