Hello,

Thank you for reaching out. If you are using the SmarterMail free server as an outbound gateway for your scripts to send messages, then it would be a good idea to whitelist the server's IP address in the Settings -> Security -> Whitelists section on your server that has the domains on it. This will allow the server to bypass SMTP authentication. However, it is not recommended to turn off authentication for your domain, as this can lead to spammers and third parties using your server to send spam.

I hope this explanation helps. 

Thank you.

Zach,

Thanks for the response and I will try whitelisting on the server hosting the domain, but that still doesn't quite make sense to me.

How is this any different from somebody on another service emailing this domain, and why does SmarterMail reject this form message when it arrives just fine on Yahoo and Google? Is it because the form FROM domain is the same as the recipient domain, how is the SmarterMail server hosting the domain mail even in the mix when it comes to SMTP authentication?

Hello, 

Thanks for the follow-up. Yes, this is because the form FROM domain is the same as the recipient domain. This is done to prevent spoofing. To send as a domain on SmarterMail you should need to authenticate first. 

I hope this helps. 

Kind Regards,