Category: dkim
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Message Header Analyzer and Double DKIM
If you have SMTP email routing that goes through multiple systems, and more than one of these stamps a DKIM header you should get dkim=pass at the receiver. But if one of these email servers modifies the message body then DKIM for all the previous DKIM signatures will fail. So to resolve this, and not…
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Improving Exchange Online Email Deliverability Through Third Party Filtering Services – Trusted ARC Sealer
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 in Exchange Online. Trusted ARC Sealer is a feature of Exchange Online to allow you…
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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…