Client was not authenticated to send anonymous mail

Unfortunately, you can't send a gift anonymously. No matter how you send it from your account, your recipient will see your Steam profile name and/or the e-mail address that your account was registered with. Even if your change your community profile name, they can look at the previous names you've used. Allow anonymous relay on Exchange servers | Microsoft® Docs Jul 07, 2020 Master The Art Of Anonymous Email Addresses - CTemplar Apr 30, 2020

How to send anonymous emails - Quora

How Do I Get an Anonymous Email Address? (with pictures) Jun 24, 2020 How to Create Anonymous Email to Protect Online Identity

Making Responses Anonymous - SurveyMonkey

Jul 06, 2020