メール
最高の記事
Gmailの新スパム規制対応全部書く
https://zenn.dev/ken_yoshi/articles/gmail-new-requirements-2024
その他文献
https://qiita.com/nfujita55a/items/5848fcfbbe6cbf7d98c3
https://am.arara.com/blog/07
https://baremail.jp/blog/2022/09/06/2752/
https://zenn.dev/yktakaha4/articles/technology_for_sending_email
https://scan.netsecurity.ne.jp/article/2024/02/26/50634.html