While admins can change their team name in Tandem preferences, they aren't currently able to update the email domain.
Having the proper domain listed in Tandem allows for a few admin settings to be utilized:
Allow anyone with a verified email address (ie: @roastedmarshmallow.co) to automatically join
Restrict access to members of the organization (ie: prevent users without roastedmarshmallow.co email addresses to join)
If you have changed your domain (ie: it used to be toastymallows.com but it's now roastedmarshmallow.co) and want to update your domain and the email addresses for your team, message us in Tandem or email us at email@example.com
If you are using a completely new domain with new email accounts, you may want to simply create a new Tandem team and abandon your older one.