Hosted Exchange

http://www.one-info.net/3701/ExchangePakketten.html

Exchange for Linux

http://wirednless.com/2009/01/exchange-replacement/

Zarafa

http://www.zarafa.nl/
http://www.zarafa.com/
wikipedia → Zarafa
wikipedia → Z-Push
wiki → http://www.zarafa.com/wiki/
forum → http://forums.zarafa.com/
http://www.msb.co.at/docs/zarafa/zarafa_technical.pdf
http://www.zarafa.com/wiki/index.php/Exchange_to_Zarafa_migration

Scalix

http://www.scalix.com/

Zimbra

http://www.zimbra.com/
wikipedia → Zimbra
Hosted Zimbra → http://www.tapit.nl/index.php/online-diensten/16
Hosted Zimbra → http://www.zimbra.xxlwebhosting.nl/index.php