After Migrating to exchange 2013 from exchange 2010, the old expired certificate is bound to SMTP service, even after installing a new certificate which is assigned the IIS and SMTP service.
We are not able to remove the SMTP assignment from the expired certificate, as it is greyed out in the ECP. Also, tried exchange PowerShell to change the assigned service to none but, still no luck. Can anyone provide a solution? Our new certificate is due for renewal in two weeks and we need all expired certificates removed.