Mail Setup

[Robert Slade]

Hi,

I've tried goggle and the howtos but all I have managed to do is get
confused. 

What I am trying to do is setup a mail server that can handle up to
about 20/25 users, some on my network and some external. Currently most
are managed using mercury under W2k, but I would like to setup a
dedicated mail server to do the job. The other factors are multiple
domains and the need to support Webmail and as the users will be using
Windows, a virus checker, spam suppression and I that am new to Fedora/
Linux.

I have had a 'play' with postfix and that looks OK as a MTA, my real
problem is what next? There are a number of howtos (and books) covering
mail setups but I have not been able to find anything that discusses the
relative merits of the different MTUs etc. 

For fear of starting a my MTU is better than yours argument, what is the
best setup to support the above and where can I find documentation on
how to set it up?

Thanks

Rob