In February of 2024, Google and Yahoo implemented new bulk email requirements, as mentioned in GreyMatters in December 2023. In April of this year, Microsoft revealed its own restrictions on bulk email senders. These restrictions will be implemented in May 2025. 

To meet the requirements of Google, Yahoo and Microsoft, bulk emailers must enable these mechanisms:

• Sender Policy Framework (SPF) – helps to prevent domain spoofing by providing a means for senders to identify the email servers that are approved to send emails from their domain.
• DomainKeys Identified Mail (DKIM) – attaches a digital signature to outgoing emails to verify the sender’s authorization and confirm that there was no tampering with the email on its route to the recipient.
• Domain-based Message Authentication, Reporting and Conformance (DMARC) – this provides email senders a means to specify the actions to be taken if an email fails authentication, as well as providing reporting on email authentication results.

Additional requirements for bulk senders include:

• Spam rate restrictions: Sender spam rates must be kept below 0.10% and senders should “avoid ever reaching ≥0.30%.  
• Support for one-click unsubscribe option.

Even if you believe your organization has its email strategy set to meet these requirements, there’s something to keep in mind: If all, or most, emails from various functions within the organization – sales, marketing, business development, etc. – come from the same domain, all emails sent by these functions will count against the limit. Also, it may be that members of these functions are not aware of the limitations, so it is crucial that everyone in the organization who sends bulk emails is aware of the restrictions.