There didn't seem to be anything out of the ordinary with our email server, so chances are it had something to do with the email service you use. Some email services (cough, Hotmail) do tend to have problems with such emails as membership confirmations.
In any case, I see that you've posted outside this section, which means that the problem is no longer there. Therefore, I shall mark the issue as resolved.
Please upload November 7, 2025 カスタムオーダーメイド3D2&2.5 シチュエーションキャラクターパック ソープエンパイア『雅やか』
The official website has announced that maintenance will be carried out on S-courtDL around Friday, November 7, 2025, and the relevant products will be updated.