Wow! 40411 views and 105 replies only on one relevent excahange thread... just google this issue you will see the massive amount of frustration of community whom love the mac and can not get the exchange server to work properly despite latest 10.8.3 Lion upgrade.... all this yet Apple people have no word!!!
It is shame that my $1200 mackbook not working with such crucial mail app on exchange!!!!! nor the Apple people lack the will to make a statement.
I think after long hours wasted on this issues and error and trials... I am eagerly waiting for good fix by Apple for once...
I hope that day will come soon...
I know exactly what you have struggling with.
I was lucky enough however to be able to switch my Exchange account to an IMAP account - my workplace provides the server access I need for that.
Under IMAP, checking mail is vastly faster - what it should be. I don't know if this is because the sheer amount of synchronization overhead is reduced or just that the synchronization is simply going faster. One thing that has truly gone away though are the interminable spinning-gray-windmills as you wait while content is 'Loading'. These were starting to appear on an infuriatingly more frequent basis and were swiftly approaching true "showstopper" status.
Executing the change to IMAP almost got me into trouble though - if you try it yourself, do it carefully and deliberately. (I nearly lost three months of mail that was still on the Exchange server.)
On another topic, somewhere over the course of the last two OS upgrades, the Mail app's once reliable search engine has become extremely unreliable. In many ways this is just as serious a problem as the Exchange account dysfunction.
I share your dismay about the tattered state of the Mail app. It seems to be on a development downslide as critical features are not being fixed by Apple. Which is a shame because it used to be an enormously powerful tool that really harnessed the integration of the Mac OS. It still is a powerful tool, but not a reliable one. And you can make costly mistakes with unreliable powerful tools.
Shutdown Mac Mail.
Go to /Library/ in Finder and copy and delete the Mail Folder (make a copy of it somewhere before hand). This folder will be under your User Profile (ie /Users/<username>)
Go to Preferences, then Mail and Contacts and then highlight the Exchange account and delete it.
Go to /Library/Cache/ folder and delete all the contents under it.
Go to /Library/Cookies/ folder and delete all the contents under it.
Go to /Library/Saved Application State/ folder and delete all the contents under it.
Go to Mac Mail and recreate the account
Yes, it work for me.