Thanks for response!
I didn't notice any threads group it might not work or it doesn't exist, I don't know. Buy the way, all mails was unsorted and as result useless.
My fix is simple, in Roundcube_0.php there is two options for $rb->force_order for e-mails tab function, originally second one in force and first is commented, I just uncommented first and commented second, after that all mails goes in order by date (last mail in top).
Also if you replace "force_order" by "order" it will allow sorting by column name click (but records unsorted on default) if you can tel how to setup default sorting by date, it would be great!
About mail, I'll check log bit later.