We are running Exchange 2007 SP1 on Windows 2008 SP2 servers. Our HQ is SiteA, and contains Mailbox, Hub Transport and CAS servers.
We have multiple AD sites, each with their own Hub Transports, and the HQ Hubs also have legacy routing group connectors to 2003 Bridgehead servers.
I have noticed the following error on some of the Hubs:
There is no valid SMTP Transport Layer Security (TLS) certificate for the FQDN of Hub1.domain.com. The existing certificate for that FQDN has expired. The continued use of that FQDN will cause mail flow problems. A new certificate that contains the FQDN of Hub1.domain.com should be installed on this server as soon as possible. You can create a new certificate by using the New-ExchangeCertificate task.
However, we aren't having any mail flow issues from what I can see.
Do we need to do anything and, if so, what? :-)