When sending emails to a Google Workspace email account and/or Gmail, you may receive a rejection notice from Google which contains something similar to the following:

550-5.7.26 This mail is unauthenticated, which poses a security risk to the
550-5.7.26 sender and Gmail users, and has been blocked. The sender must
550-5.7.26 authenticate with at least one of SPF or DKIM.

This is because Google didn’t know if it could trust the servers sending the email or not and this relies on one or more methods to authenticate the servers and these are likely missing.


To correct this error, you must ensure you have a valid Sender Policy Framework (SPF) record for your domain.

We also recommend ensuring that DKIM signing has been configured and enabled for your domain.

These two items are control mechanisms for email to give assurance that the server sending them is allowed to on behalf of your domain. Not only will it correct issues with gmail rejecting email, it will increase the email deliverability for many other systems as well.


If you need assistance, Conetix customers can simply contact our support team and they’ll be able to review your SPF and DKIM settings on your behalf.

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