If you set up a custom email domain in iCloud+, it will also appear in the Mail app on iOS, iPadOS and MacOS. It mostly works but I have noticed that messages that you send that way to not have a DKIM (Domain Keys Identified Mail) signature. In modificare https://herb-grinder93715.gynoblog.com/15895301/5-semplici-dichiarazioni-circa-icloud-mail-explained