At this time our US SMTP is being blocked by the Cloudmark Sender Intelligence block list. We've dealt with the cause and have started the de-listing process.
If you receive a bounce message, please do not attempt to delist the server yourself via the URL in the error message. We're taking care of it.
We'll update this post when the server has been removed from the list.
We've confirmed that there are no further blocks by Cloudmark.
Cloudmark have stated that they have de-listed the server IPs. We'll continue to monitor until we see no further blocks in the mail logs.
We're still working with Cloudmark to have the US SMTP and MX servers delisted.
We've discovered that the US MX servers are also blocked. This could cause mail forwarding to fail if the final recipient domain is using the Cloudmark block list, so we've requested delisting of those as well.
