Issues sending to Outlook.com hosted addresses

We are currently seeing some issues sending TLS encrypted mails to Outlook.com hosted email addresses.
This appears to only be affecting some of the Outlook.com hosted server ip addresses intermittently
213.199.154.87 / mail-db34087.inbound.protection.outlook.com
213.199.154.23 / mail-am14023.inbound.protection.outlook.com

If messages fail to be delivered, you will receive a bounce message similar to the following:

TLS connect failed: timed out; connected to 213.199.154.87.
I’m not going to try again; this message has been in the queue too long.

In the interim we have disabled TLS encryption to the affected addresses.
We are currently unsure if this is a Microsoft issue, or a China Firewall Issue, so this may or may not resolve the issue.

We will update this post when we have further information.