
When you first set up Mailgun to send emails, you may find there is a "via mailgun.org", "via mailgun.us", or "via mailgun.info" warning for the email in the recipient's mailbox.
This warning means you haven't authorized Mailgun to deliver emails for you, so the mailbox provider considers that sen…

When you first set up Mandrillapp (AKA Mailchimp Transactional Email) to send transactional emails, you may find there is a "via mandrillapp.com" warning for the email in the recipient's mailbox.
This warning means you haven't authorized Mandrill to deliver emails for you, so the mailbox provider…

When you first set up SendGrid to send emails, you may find there is a "Via SendGrid" warning for the email in the recipient's mailbox.
This warning means you haven't authorized SendGrid to deliver emails for you, so the mailbox provider considers that sent from SendGrid instead of your brand…

When you first set up Zendesk to send emails, you may find there is a "Via Zendesk" warning for the email in the recipient's mailbox.
This warning means you haven't authorized Zendesk to deliver emails for you, so the mailbox provider considers that sent from Zendesk instead of your brand…

This tutorial provides step-by-step instructions on how to set up DMARC starting from p=none, transition to p=quarantine, then to p=reject using DMARCLY, a dedicated DMARC analyzer service.
The tutorial assumes no prior knowledge whatsoever of DMARC or DMARC reports…

When you examine the email headers inside a message, it is not uncommon that you find multiple DKIM signatures in a single email message.
Similarly, you can run into multiple DKIM signatures in a single email stream in some DMARC aggregate reports…