It is blank, here I'm using sending mail in format as described user@IP.Address because there is no static IP and it seems that DNS won't resolve name of my server to the current IP or something similar, so qmail is rejecting arrived mail like
This domain can not be found in rcpthosts, and so on...
I have tried with adding some mail filters like accept User@* but it won't work again. If anybody has same problem and solution

please share it with us
Thanks