What does it mean when a newsletter autoreplies saying the sending domain doesn't match the email domain?

Email marketer from Mailjet Blog explains that a mismatch between the sending and email domain suggests a potential authentication issue. The recipient's mail server is likely configured to reject emails where the domain in the 'From' address doesn't align with the server used to send the email. This is often a security measure to prevent spoofing.

Email marketer from Gmass states that you need a domain that aligns with the `From:` header, the domain used to authenticate with SPF, and the domain used to authenticate with DKIM. This is a MUST these days

Email marketer from EasyDMARC explains that to fix this you must authenticate your emails correctly using SPF and DKIM and then ensure that the "From" header aligns with either the SPF or DKIM authenticated domain.

Email marketer from Reddit shares that in most cases, the From address needs to be an email hosted on the sending domain. Otherwise, strict mail systems reject the email due to authentication checks.

Email marketer from Webmaster World explains that the "From:" address in an email header must match the actual sending domain to pass SPF and DMARC checks. This is a standard requirement by many email providers to combat phishing and spam.

Email marketer from Sendinblue Blog shares that this error often indicates an issue with SPF (Sender Policy Framework) records. If the sending server isn't authorized in the domain's SPF record, recipient servers may flag the email as potentially fraudulent because it's being sent from a server that isn't explicitly permitted to send on behalf of that domain.

Email marketer from StackOverflow explains that the autoreply usually means that the receiving mail server is strictly enforcing domain alignment policies (like DMARC). The email failed either SPF or DKIM checks and the DMARC policy is set to reject misaligned emails.

Expert from Word to the Wise shares that the error message means that the receiving mail server is performing strict sender authentication checks. The server is verifying if the sending IP address and domain are authorized to send emails on behalf of the domain in the 'From' address. This involves checking SPF, DKIM, and DMARC records, and if any of these fail, the server might reject the email.

Expert from Email Geeks suggests it might be an Asana task creation alias rather than a real recipient. He suggests checking the audit trail for that address.

Expert from Email Geeks suggests that the customer might be using a personal mail server with strict settings, and it's probably not changeable. She advises that unless the domain covers more than 1% of the address list, it's best to remove the recipient.

Expert from Spamresource explains that this is a common sign of an SPF or DMARC failure. The receiving mail server is checking if the sending server is authorized to send emails on behalf of the domain specified in the "From" header. If the SPF or DMARC records are not properly configured, the email will fail authentication and might be rejected.

Documentation from DMARC.org defines DMARC as a mechanism used to allow receiving mail servers to determine if incoming mail from a domain is authorized by that domain's administrators. DMARC builds upon SPF and DKIM to provide more robust protection against email spoofing and phishing attacks by allowing domain owners to publish policies about how recipient servers should handle messages that fail authentication checks.

Documentation from RFC Editor explains that Sender Policy Framework (SPF) allows domain owners to specify the mail servers authorized to send email on behalf of their domain. Recipient servers use SPF to verify that emails appearing to originate from a given domain were sent by sources authorized by that domain's administrators.

Documentation from DKIM.org explains that DKIM (DomainKeys Identified Mail) is an email authentication system designed to verify the authenticity of email messages. It allows an organization to take responsibility for a message by attaching a digital signature to it, which can then be verified by recipient mail servers to confirm that the message has not been altered in transit and that it was indeed sent by the claimed sender.