Where can I change the account name in Zendesk Support?
Your account name is the one populating in the page tab next to the favicon from your agent interface and, by default, in the subject line of the email notifications sent from your account. To change the name of your Support account, go to Admin ( ) > Settings > Account > Branding.
The account name is different from the subdomain. Changing the account's name doesn't change the email address of your account. If you want to rename your subdomain, see the article: Renaming your subdomain.