Thank you! The 4 option works the way I want. I put # instead of 4 for directory option in parameters for "12. PBX Integration".

While looking at all these jazz I obviously wanted to see parameters for other PBX Integration options (2 and 4 digits vs 3 digits I use). smile
I guess it somehow affected my mailboxes. smile
Now in "14. Messages Waiting" I have messages but no mailbox numbers assigned to them. Looks like nobody can retrieve those - is this right? Since they are "stray" messages - not belonging to any mail boxes...
Is there a way to listen to them? Or assign them to mail boxes? I am afraid there were some real ones besides my tests...

I also lost passwords for mail boxes and class of services defaulted to 1. But all of these is minor. I mostly concerned about messages being lost...

Thank you so much for you patience and help...