Hello Mr. Hazel,
All is clear now I forgot about the possibility of hints getting lost!
Obviously, I oversimplified the process. As you have shown, there is
much more to take into consideration.
I'm continuing to learn Exim and yesterday I created my first mail loop
while trying to install SpamAssassin:) But I figured it out later.
Thanks very much for your comprehensive reply.
Regards,
Sergei Gerasenko