Mail server recomendations (was: is the list the right place to ask?)

[Ray]

> On 2/10/07, Ray <ray at stilltech.net> wrote:
> > Hello,
> > Just wondering if this list is the right place to ask for suggestions
> for
> > what package to use for various purposes?
> 
> Yep... what did you have in mind?
> 

I'm looking for a package (or set of packages) that would provide a mail
server with the following capabilities

minimally:
pop and smtp access that could handle 20 to 100 domains and 200 to 2000
mail boxes.(allowing some room for future growth)

ideally: also provide a web interface for individual users and also for
administration on a per domain and whole server level.
we have several customers that need to be able to administer their own
domains, (Read this as I don't want ten calls a day saying "I forgot my
password") but we don't want them touching others accounts. 

spam and virus scanning would be a definite plus, but from what I have
read, these two parts are fairly straight forward.
We have recently changed the web server from M$ to FreeBSD and now we're
trying to change the mail server too. 
Thanks for any pointers or suggestions.
Ray
> -- 
> Juha
> http://www.geekzone.co.nz/juha