1. m3aawg

古い? Gmail 要請との比較 /table

Google and Gmail don’t accept allowlist requests from email providers.

We can't guarantee messages sent by email providers will pass Gmail’s spam filters.

New Minimum Requirements for Sending Bulk Mail to Gmail and Yahoo October 31, 2023 https://www.m3aawg.org/blog/SendingBulkMailToGmail_Yahoo

1.1. The Requirements

Here is a summary of the requirements for bulk senders scheduled to begin in early 2024:

Implement both SPF and DKIM - Mail sent to these providers must be sent using Return-Path domains that have SPF records and messages must be DKIM signed.
Send with DMARC - The visible From: domain of messages must have an existing DMARC policy record in DNS. The required policy at this time is p=none.
Send with an aligned From: domain - The visible From: domain must align with either a DKIM signing domain or the SPF domain, or even both. M3AAWG strongly recommends aligning with a DKIM signing domain to mitigate the risk of an SPF Upgrade Attack, where a domain with a too-permissive SPF record can be successfully spoofed under some conditions.
Valid forward and reverse DNS - Mail must be sent from IP addresses that have valid reverse, or PTR, records in DNS, and those PTR records must resolve to hostnames that resolve back to the IP address. This is also called “Forward-Confirmed Reverse DNS” or “FCrDNS” for short.
One-click unsubscribe - Commercial mail must have the one-click unsubscribe functionality as described in RFC 8058
Low spam rate - A user reported spam rate under 0.3% is the required threshold