What about Lotus Notes? It runs on Unix.
I worked for a University and they supported ~12000 students on a few midsize servers. It has a pretty nice Email client as well as webaccess.
I have seen Exchange running at a local Navy datacenter. It was supporting about 25k users, but the boxes were HUGE.
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What about Lotus Notes? It runs on Unix. I worked for a University and they supported ~12000 students on a few midsize servers. It has a pretty nice Email client as well as webaccess. I have seen Exchange running at a local Navy datacenter. It was supporting about 25k users, but the boxes were HUGE.