question about hardware configuration of a webmail server

[Herve Ballans]

Hi,

I'm new on this forum and I want to install a webmail (horde/imp) on my
service.
Actually, I have a sendmail server.
This server deliver mail for 250 peoples, principally some researcher,
so they are often in travel at the outside.
I want to dedicate a server for the webmail service wich compose by a
Linux RedHat 7.2 distribution, Horde 2, IMP3, PHP4, Apache and MySQL

My question is about the hardware configuration of this server.
Wich type of PC must I buy to have a good QoS for 250 peoples ?
power processor ?
RAM ?
disks (IDE, SCSI) ?

I think it's depends on the number of simultaneous consultation...

I've read the Horde Administrator's FAQ, but no information has
mentionned for that...
If you have any suggestions or any experience, thank's a lot

--
Cordialement

Hervé Ballans
Responsable informatique
CNRS - LPS