Hi all, I'm going to deploy email service for an organisation, which bases its SMTP server on Postfix. And I'm now calculating the number of users per one working email server with certain hardware requirements. I'm not sure how powerful is enough, but if I take a server like, say, HP ProLiant G7 (Quadcore 2.1Ghz, 4Gb DDR3 memory), how many people for that configuration is optimal (and how many can send mail concurrently)?? The organisation may have about 300,000 users presently and up to 1 million users in the future. Anybody can give me advice on this? Thanks so muchhhhh!!