which server model is the best

[uji_amira]

I am in the process of migrating my mail servers. I need to buy a new hardware for the email system. Right now, I hv 3 model types - HP, Dell and IBM. I need your sincere opinion (those who have use any of the servers) on which is the best model to replace my old machine - the system are email system..running on either Linux or OES Novell..The mail system are Lotus/Groupwise..It will be supporting up to 1500 mailbox.It will be a very very heavy utilisation of CPU and memory and some users are located at other sites..
Really appreciate your sincere opinion..thanks..

[ServerMan]

Are you looking towards rack mounted or towers? If rack mounted, give me some specs and I can give you a quote to compare with. If you want a closer look at our servers go to www.RackLogic.com. I am the technical sales exective there and I can work something out for you.