I often get requests for name changes of established customers. Maintaining the old records as an alias is easy if using an address policy. Here’s how I like to do this:

The Disable and Enable of the address policy corrects the email address by adding the new rules.

Old addresses are preserved, new ones are added:

(get-mailbox jbilinski).emailaddresses

SIP:[email protected]
sip:[email protected]
smtp:[email protected]
X400:C=US;A= ;P=Contoso;O=Exchange;S=Bilinski;G=Jamie;I=JCB;
x400:C=US;A= ;P=Contoso;O=Exchange;S=Bilinski;G=Jan;I=JCB;
SMTP:[email protected]
smtp:[email protected]