Anyone else having issues sending through the gateway?

As the title says, curious if anyone else is having issues sending mail through the gateway?

Below is an example of the error we have been receiving, it looks like Comodo had a cert expire?

Receiving server: (
Remote Server at ( returned '400 4.4.7 Message delayed'
2/26/2016 3:43:36 AM - Remote Server at ( returned '451 4.4.0 Primary target IP address responded with: "454 4.7.5 Certificate validation failure, Reason:CertificateExpired." Attempted failover to alternate host, but that did not succeed. Either there are no alternate hosts, or delivery failed to all alternate hosts. The last endpoint attempted was'