Improving Exchange Online Email Deliverability Through Third Party Filtering Services – Trusted ARC Senders

When you receive emails into Exchange Online and you filter the external messages before arrival with a third party filter such as Mimecast, Proofpoint or others, then you can have DMARC failures that result in messages being junked or quarantined. This is a new feature to Exchange Online to allow you to trust the DMARC… Continue reading Improving Exchange Online Email Deliverability Through Third Party Filtering Services – Trusted ARC Senders

DMARC Quarantine Issues

I saw the following error with a client the other day when sending emails from the client to any of the Virgin Media owned consumer ISP email addresses (virginmedia.com, ntlworld.com, blueyonder.com etc.) mx3.mnd.ukmail.iss.as9143.net gave this error:vLkg1v00o2hp5bc01Lkg9w DMARC validation failed with result 3.00:quarantine In the above, the server name (…as9143.net) might change as will the value… Continue reading DMARC Quarantine Issues