Changing the Primary Email Address in Exchange 2007
Amending the Primary Email Address in Exchange 2007
It is necessary on occasion to make a new email address to add to an existing one for a user, and then to make it the default one so that it can be seen and replied to by mail recipients.

Exchange 2007 makes the process though more difficult that Exchange 2000 and 2003 did. In previous releases it used to be possible to make a new email address the default just by altering the “set as primary” marker. This though cannot be done in 2007 as the option of “set as reply” is not available. Therefore it is necessary to uncheck the marker that allows for “automatically update email addresses based on recipient policy.” Once this marker has been removed then the option for “set as reply” is available and can be applied to the new email address. One last step is to manually alter the primary email address within the AD.

Article written by MyComputerAid.com