单项选择题 Your company has an Exchange Server 2010 organization. A user named User1 is configured as a Delegate for a user named User2. You need to ensure that User1 can add User2 in the From field when sending email messages. Messages that contain User2 in the From field must display User2 as the message sender when recipients receive the messages.  What should you do（）？

单项选择题 Whichofthefollowingprovidestheunderlyingtrustinfrastructuretoenableeasyandsecuresharingofinformationorganizationsandincross-premisesorganizations？（）

单项选择题 WhichofthefollowingisanidentityservicethatrunsinthecloudasthetrustbrokerandisusedbyExchangeServer？（）