@DLloyd1 Gmail and Yahoo are constantly updating their guidelines as we get closer to the February deadline for when these requirements will be enforced more strictly, which is why you’ll likely see changes in their email sender guidelines over the next few months (Gmail and Yahoo).
DKIM is configured for your sending domain and would need DNS changes as outlined in our Knowledge Base, whereas RFC 5321 states that SPF is primarily checked against the MAIL-FROM domain (also referenced as the bounce or return-path domain). If you’re sending from the shared swimlanes, no modifications are needed with your IT team, as this is already set for you. On the other hand, if you’re sending with a dedicated IP, our Deliverability Operations team will reach out with any DNS adjustments to be made along with the corresponding records. They will also send you an alert if DNS errors are detected that may affect your sending and follow up with multiple warnings.
Lastly, our systems are designed to send in a round-robin fashion, based on the volume and frequency of your sending, and to properly load balance to ensure your emails are sent in a timely fashion. You must also keep in mind that how quickly a mailbox provider accepts messages for delivery can vary based on the sending practices followed and reputation on the respective platform. However, I understand your concerns and will review this with our internal teams for further consideration in improving our systems.