Sender Requirements

It was back in 2023 when Google and Yahoo simultaneously announced that they would start penalizing senders who did not follow their guidelines. The announcement caused some panic because many domains didn’t have DMARC records, some ESPs only DKIM signed messages with a shared domain, and many ESPs did not support RFC 8058 which describes the required one-click unsubscribe mechanism. Now in 2026 the dust has settled and other providers have since announced enforcement of their own bulk sender requirements to little fanfare; mainly because all of the heavy lifting was done achieving compliance with Google and Yahoo. ...

2024 Update: Gmail and Yahoo! Change Their Sending Requirements Last updated: 10 August 2024 Refer to Chapter 8 (Sender Reputation) and Chapter 11 (Email Authentication) of Email Deliverability Explained (2nd edition) for background information on topics discussed in this post. Back in October 2023 Google and Yahoo! simultaneously announced that they would begin enforcing new requirements for bulk senders from February 2024 onwards. By June 2024 all of the new requirements are officially being enforced. ...