You have a SharePoint Server 2010 server farm. You need to ensure that users can send e-mail
messages to document libraries. What should you do?

A.
From Central Administration, configure the incoming e-mail settings.

B.
From Central Administration, configure the Web Application outgoing e-mail settings.

C.
From Document Library Settings, modify the Custom Send To Destination value.

D.
From Site Settings, activate the E-mail Integration with Content Organizer feature.

Explanation:

How to Setup Mail Enabled Document Libraries in SharePoint 2010
http://blogs.technet.com/b/praveenh/archive/2010/12/22/how-to-setup-mail-enabled-documentlibraries-insharepoint-2010.aspx