Debian Web/mail/ftp server operation

I plan on setting up a web server that will include POP3 and SMTP services. I never did any real server configuration before and nor I done any unix/linux based server configurations that include both mail and web (I know how to manage and unix machine with multiple users).
I am pretty much thinking of having each website as a separate user account in my debian system. The user can then ssh my server to run statical shell scripts I give them permission to since they will have no other access to anything else on the system. Of course commands like ls, mkdir, mv, cp, ping...etc will be accessible. There will be no viewing outside of they're home directory, they'll be jailed when in ssh mode or ftp...etc. Now I would like for them to update they're sites via vsftpd and like said they will be jailed in they're home directory. They will have full permissions except group and others will have no rwx permissions.
I will of course link my apache virtual hosts to each corresponding user account's mydomain.com directory. Now is there a way to give the user full permission to a folder without letting them change the name?
Since one user account contains the website will will be a master account.
Now for mail configuration I will have the mbox in the master account.
I would then write a few scripts to add subdomains and to allow more email address accounts to be made with the corresponding domain.
Would this be a good linux web/mail server configuration?
I intend to serve a site for my friend, two sites for me and one for my dad. Maybe others if I'm good, idk yet.
Also just to add I have port 80 open and 25 with my ISP...etc and I have a DDNS manager from my ISP.
Thanks for the advice and criticism.

 

Have you thought about using this tutorial: http://www.howtoforge.com/perfect_setup_debian_etch ? Afterwards you can install ISPConfig. This will do almost anything you need.

 

Thanks I did look at the tutorial. I have two questions though. The first is why did the tutorial setup a DNS server with BIND? The second is that ISPConfig is basically just a front panel for managing multiple web sites right (like cpanel or something)? There is a admin version and a host version both accessible through HTTP on port 81? Now whats the popularity of ISPConfig in the real world of hosting? I know most pros make they're own interface but would ISPConfig but sufficient? You say it would work for most of my things, but what won't it work with? I know I will have to use proftpd which I don't really prefer over vsftpd.
Also was the tutorial is written with intentions of accommodating multiple hosts with a site and several email accounts on they're domain?

Other then that if I was to use my own interface, would my original method be pointing in the right direction or way off where I would be laughed at? I know I could make a web interface where users can login through a php interface to manage they're site instead of ssh. But The tricky part of that would be connected the interface to the linux side of things.

As you can see I'm lost. I think I will go give ISPconfig a shot though.

Just thinking about the whole thing and would ISPconfig have users have they're own user account or would this be entirely through MySQL or something?

 

Thank you very much till and falko,
Okay I have a setup like in the tutorial. My last question is how can I configure ISPconfig without a domain. I'm only doing this since I don't plan on buying a domain. dyndns.org offers free ddns subdomains, right now at least at this time my server will have a free subdomain through dyndns.org. The other websites being hosted will be apache virtual hosts setup through ISPconfig and will have their own domains. When I tried to setup ISPconfig with my subdomain it would not work.

So I think I will just have my server's hostname as the name of the computer like dell poweredge and the domain left blank? This is a possible configuration no? Is there a default I could use like "hostname.local" used in the macs? Thanks again.