When managing users, we usually also find that we need to manage e-mail settings or even e-mail systems. Microsoft Exchange is the most common e-mail system but I also have quite a few customers running other e-mail systems, such as IBM Lotus Notes.
In order for FIM to also manage Exchange, there are some configuration settings and permissions required.
Basically, what happens is that FIM adds attributes to the object in Active Directory and makes a call to Exchange to update the recipient.
In order to do this, the AD MA account needs to be a member of the Exchange Recipient Management group.
If there is a need for more complex Exchange management, such as moving mailboxes, the built-in functionality will not be enough. I would then suggest that you take a look at some third party PowerShell MA.
In order for us to manage the attributes used and required by Exchange, we will need some knowledge about Exchange. There are, for example, multiple types of recipients to deal with...