So reverse DNS entries are set by the ISP on the static IP’s that are assigned to you and used by the phone system to get online. I guess I am assuming here that you are using a physical unit that’s trying to send out email over your internet connection. Not sure what the situation is with reverse DNS entries for IP’s provided by a cloud provider if this is a virtual environment but if it is you would need to check with your cloud provider how to get that setup.
SPF records are easy to Google and setup based on some of the guides that are provided out there.
Correct, I have a physical unit that is using the internet to send a mail. I am not getting a static ip by my provider but a dynamic one.
I am also not using the providers DNS but Cloudflare DNS if that has anything to do with it.
Pointing out again that (mail [email protected]) from the cli works and I receive the email. Only the missed call notification module fails to send it there.
I will Google spf record setup and check my domain as per your instructions.
Please confirm that it gets delivered even when the From: Subject: and body are identical to those of the failed message from Missed Call Notifications.
Remove the attachment. In FreePBX, tell it to not include the VM as an attachment. Or, configure your PostFix to relay using a clean smarthost.
If you want GMail to accept your email with an attachment, you need to configure the mail system properly, which includes those records that you said you don’t know about. If you don’t know how to configure SPF and rDNS at a minimum, then you need to just use a legitimate SMTP relay from someone who knows what they’re doing.