As you know, SharePoint comes with webparts which allow to display the inbox, tasks, calendars and others folders from the Exchange mailbox.
Unfortunately, users have to configure the webpart to display these folders, especially the server to use.
SharePoint administrators may want to configure automatically.
If you take a look at the user profile in SharePoint, you can see some fields related to Exchange (such as Outlook Web Access URL).
The first thing to do is to map the OWA URL field in the SharePoint profile with the correct AD attribute, which is msExchMailboxUrl.
Then, if you open your profile this property will not be shown (even if set it to be visible). This is because the AD attribute is empty.
So, open your AD console and locate your user account (of course, this will have to be done to all user, and as you may have a lot of users a script will be welcome).
Switch the console in Advanced features view mode (menu View\Advanced features) to be able to view to Attribute editor tab.
Then locate the msExchMailBoxUrl attribute and update his value with your Exchange access server (‘front-end’); use the internal URL, SharePoint is very intelligent and, if your AAM are correctly configured, will switch the URL in case of remote access.
Then start a user profile synchronization in order to populate the field.
Finally, open your My Site and add the one (or more) Exchange webpart; you will see the Exchange server field automatically populated. You can also try a remote access to check the translation – in this case, you may have to re authenticate if you’re using FBA for Outlook Web Access.