When you send emails to personal Gmail accounts, Google randomly checks if they are verified. To ensure that your messages are delivered as expected, we recommend that you set up SPF or DKIM for your domain. Messages without at least one of these verification methods will be rejected with error 5.7.26 or marked as spam.
SPF (Sender Policy Framework) and DKIM (DomainKeys Identified Mail) are two verification methods that help prevent spam and phishing. SPF checks whether an email from a specific IP address can be sent on behalf of a specific domain. DKIM adds a digital signature to the email header to verify that it has not been altered during transport. By setting up SPF and DKIM, you can verify the authenticity of your emails and ensure they are not marked as spam.
If you use an email service provider, check whether it verifies your organization’s email with SPF or DKIM. This applies not only to Gmail but also to Hotmail.
Starting February 2024, these new requirements will also apply to parties sending “bulk mail” to Gmail users. Bulk senders must authenticate their emails using email standards SPF or DKIM. In addition, bulk mails must include an unsubscribe link that allows users to unsubscribe from further emails from this sender with one click. These unsubscribe requests must be processed within two days. As a third measure, Gmail will adopt a certain spam level. Bulk senders must stay below this level, otherwise their messages will be marked as spam. In addition to Google, Yahoo will also impose stricter requirements on bulk mail. Bulk senders are defined by Google as parties that send more than five thousand messages in one day to Gmail users.
Domain name holders must check whether SPF records have been created themselves. They can check this via https://internet.nl/test-mail/
