I understand the frustration and this exactly is the reason for Sharing this articles. all Mu emails were going to Spam folders on GMail. My users were not getting My eMails. I too want to have My own Mail Server but for those Millions who Still use these Services Should follow the Methods explained here.
Microsoft Outlook / Hotmail / Live. Yahoo Mail, Apple iCloud Mail, Corporate email servers using services such as Microsoft 365 or Google Workspace and other's.