[Exim] exim howto/tutorial ?

> hi to all that are able to shed some light with this problem i am having.
>
> i have 3 domains on my system
>
> dom-one.com
> dom-two.com
> dom-three.com
>
> and 3 users on my system
>
> userA
> userB
> userC
>
> * at this point in time, exim is a fresh install on the system. i have
> been through the eximconfig and entered relevent details for my
> network and local domains hosted on this box etc etc.
>
> from my interpretation of the docs, i assign email addresses to these
> users by the following entries in the /etc/aliases file, specifically
>
> userA@???
> userB@???
> userC@???
>
> so far so good....when i send mail to :-
>
> userA@???
> userB@???
> userC@???
>
> all 3 receives them
>
> now....if i send email to userA@???, userA receives this email
> where they SHOULDNT
>
> my question is
>
- how do i prevent that from hapenning ?
> - why is that so ?
>
> my current sitiuation is ...i have read the docs/manual.... but none of
> it, from my interpretation of the content, tell me about my particular
> problem. in fact...most of the documentation are very technically
> detailed....and in most cases i am totally baffled....or lost ?!?
>
> i appreciate the effort u put into sheding some light on this...
>
> otherwise...if anyone could point out to where i can find some
> "tutorials/howtos" i would appreciate it....
>
> the docs, despite its thorough and comprehensiveness, is still
> overwhelming and not IMHO a "howto/tutorial" so to speak.
>
> at this point in time , i have read all the manuals and looked at other
> examples posted on the net.
>
> i am quite eager to learn this on my own...but need some help with
> learning how to initially get pass exim's cryptic manuals and etc
>
> thanks all for your help in advance...
>
> regard
> chris g.
>
> p.s. i have tried using a particular example from one of the debian-user
> post regarding "virtual domains" etc. to no avail....