On attempt to follow the link from the e-mail sent after Primary E-mail Address for Exchange mailbox was changed, the error is shown in browser:
An unforeseen error occurred. Please contact your provider. Error ID: xxxxx.
poa.debug.log the following error appears:
Unauthenticated call to XXX. CORBA sessions must be authenticated using hub::acquire_own_cred
The issue has been reported as POA-79715.
Please contact your account manager regarding POA-79715