EMAIL: you should consider accessing with IMAP and SMTP protocols, if your server have them enabled. I was an happy Evolution user, but in the last months I had a lot of problems with it, and now I'm switching to Thunderbird, that finally is well integrated with Ubuntu, works well with IMAP and seems also faster.
CONTACTS: in Thunderbird, you can add the Exchange Global Address List as a Remote LDAP Address Book; the port 389 should be opened on Exchange server. In Evolution, I was not able to make this working.
CALENDAR: no way in Evolution. In Thunderbird, you can work with the Exchange calendar with Lightning extension and Exchange 2007/2010 Calendar and Tasks Provider, that uses EWS (Exchange Web Services). I just tried and works very well!
ALTERNATIVE: you can also try DavMail, what access to Exchange Web Services and act as a "proxy" for standard apps (IMAP, SMTP, LDAP, Caldav). But, I tried it some time, and I was not satisfied. Too many problems to solve...