Hello,
Thank you for quick response and valuable advices. Unfortunately we have a good reason for not upgrading Outlook on the workstation used by robot. Not going too much into the details, it most probably will cause bigger problems in other part of solution.
For me it is also very strange that different versions of Outlook have infuence on MAPIEx - as mails are processed directly on the server and as far as I know it is the same Microsoft Exchange server, but it doesn't change the fact that the problem is there.
To give more details: people will not use the particular folder of mailbox later on, they will use subfolders. The purpose of the robot is to distribute incoming mails between subfolders or to forward them to particular employees after analysing conditions in external tools. Subfolders were created by employees before automating the process was in use.
Regadrs,
Małgorzata