looks like i found pretty nice bug

[Сергей Владимирович]

Hello!
It looks like a bug, really.
I just installed exim4-daemon-heavy, then ran "dpkg-reconfigure 
exim4-config"; I think it should be enough to enable very basic 
fuctionality, at least for sending an e-mails to a registered users, on 
any try to send to a registered (with 
/usr/share/doc/exim4/examples/exim-adduser) user I got the same thing - 
"550 relay not permitted". I google around and didn't found any method 
to kill this message, it's very looks like huge bug package must be 
usable with it's default settings(or  dpkg runs automaticaly (after .deb 
is installed) to help to make software work correctly with it's basic 
configuration)- sendmail and postfix I set up in a almost seconds, but 
exim just refusing to work