When you run the Hybrid Configuration wizard, you receive the following error message:
Execution of the Set-HybridMailflow cmdlet had thrown an exception. This may indicate invalid parameters in your Hybrid Configuration settings.
RequiredTls flag should be set to true if TlsCertificateName is specified.
at Microsoft.Exchange.Management.Hybrid.RemotePowershellSession.RunCommand(String cmdlet Dictionary`2 parameters Boolean ignoreNotFoundErrors)
The problem can occur if the send connector or receive connector has a Transport Layer Security (TLS) name that's not in the certificate. This can happen if the certificate changed and caused mismatched names for the connector.
Rerun the Hybrid Configuration wizard. When you're prompted to specify the fully qualified domain name (FQDN) of the on-premises server that is running Microsoft Exchange Server, make sure that the name that you enter is on a certificate that's bound to the Simple Mail Transfer Protocol (SMTP) service.
To determine which certificate and domain name can be used, follow these steps:
Open Exchange Management Shell on the on-premises Exchange server, and then run the following command: