It can be changed. Please use the branding function.
The branding feature must apply for a vanity URL and be approved.
Vanity URL can be registered with business plan or above.
(1) Apply for and obtain the character string to be embedded in the URL from the vanity URL on the administrator page and “Account Profile” menu.
(2) After acquisition, various templates can be edited from the “Email” tab of the “Branding” menu.