From your current account ("From:" field should display the e-mail address you are currently subscribed under), send a message to firstname.lastname@example.org, with the following text in the message field:
change * newemailaddress
For example, if you are currently subscribed as "email@example.com" and are switching to your Office 365 email, use your UI standard e-mail address (alias) "firstname.lastname@example.org" as your "newemailaddress" (e.g., change * email@example.com).
How the Change Process Works:
A message is sent from Listserv to your "old" address, asking you to click on a link to confirm the request. Then a confirmation request is generated from each list and sent to your "new" address. You need to click on the link in each message to actually change the address. Finally, a message is sent from each list to your "new" address, to let you know that your address has been changed.