I am trying to send some emails, through hotmail (outlook.live) smtp server. I am building an app that is somewhat an email client and I need to send some custom headers to provide some functionality.
The thing is that, while other email servers (only tried with Gmail and aol) accept custom headers or other rfc described headers (custom like, X-test and rfc described "Comments" or "Keywords") hotmail does not, the email sent does not contain those headers while the ones received from Gmail or aol contain the custom header.
Does hotmail require something extra or in a different format? Or they just remove them?
