Taylor R Campbell (riastradh@mastodon.sdf.org)'s status on Monday, 29-Jan-2024 21:43:24 JST

Bonus: DKIM creates a leak incentive because the mail server cryptographically attests to every message you write, in signatures that anyone in the world can verify—even on private messages not meant for public consumption.

So you might want to rotate your DKIM keys and publish the old ones periodically:

https://blog.cryptographyengineering.com/2020/11/16/ok-google-please-publish-your-dkim-secret-keys/