[imp] general question on postfix, cyrus, imp on multiple domains

[Mark Fink]

Hello forum,

I am new to IMP (thats not the problem I hope..) and need some advice on how to start. I have multiple domains hosted at an ISP and I have web.de for the webmail. Now I run a rootserver and want to host the domains by myselve. I have to deal with the mails in this case and I want to have web access. And by the way I did browse the faq, unfortunately I did not find how to deal with the following scenario.

Here the scenario: 
everything at domainA.com => user mark
everything at domainB.com => user petsy
everything at domainC.com => user bert
mark at domainD.com => user mark
petsy at domainD.com => user petsy
... and so on and so forth

The users mark, petsy and bert should have accounts on IMP on the rootserver. Is it possible to collect the mails from several domains into one account? I have the impression that it is but I do not know how to achieve this. Do I need scripts in postfix or MySQL???

In case a user writes a new mail or replies to a mail he can select the valid sender address for this mail from a list (no seperate accounts). Is this possible? How do I achieve this?

I would like to have access for thunderbird with the same features too if it is possible. Nothing difficult, just simple mail :-)) Yust kidding... Of cause I have to say good bye to some of the features. Most important is the web access.

I plan to use the following tools for the installation:
+ IMP, Horde, Ingo, Turba
+ postfix
+ Cyrus
+ SpamAssassin
Is this a good/ usefull selection? Please respond?

A general outline on what I need and how this works together would be great. If you could provide a solution or point me to relevant articles/ books etc. this would be excellent!

If this is not a IMP question please let me know.

Best Regards,
Mark

PS: How can I access the list using thunderbird? I tried news.horde.org but I did not work.