I installed on Exchange 2013 environment in coexistence with Exchange 2010.
I installed a wildcard certificate on the Exchange 2013 and added the services IIS and SMTP to this certificate.
I have an outlook fat client which is connected to one test already migrated mailbox.
This client continually popups a security alert if I want to proceed: exchangeserver2013.FQDN
How can I prevent this behaviour before migrating other users / mailboxes?