An issue has been identified where embc users cannot send e-mail to any domain that is registered with the Hosting Group 1and1.co.uk.
All e-mails being sent to an affected domain are currently not being accepted by 1and1 mail servers due to a change of their e-mail acceptance policies. We are liaising with 3rd parties to ensure acceptance of legitimate mail from embc.
We have confirmed that delivery to email domains hosted by 1and1.co.uk fail due to current EMBC MX records using aliasing.
The RFC-16606: Update EMBC DNS records mx1 & mx2.embc.uk.com from CNAME to 'A' record has been raised to resolve the issue however we await scheduling approval from EMBC for the change to proceed.