Recipient address rejected: SMTP AUTH is required for users under this sender domain
With old iRedAPD releases, the error messages may be one of below:
SMTP AUTH is required, or it is a spam with forged sender domain
Recipient address rejected: Policy rejection not logged in
Sender domain is hosted locally on your iRedMail server, but sender doesn't perform SMTP AUTH to send email.
If this is not sent by a server or device under your control, most likely this email is spam with forged sender address.
If this is sent by a server or device under your control and you want to allow it, please add the IP address of this server/device in iRedAPD config file /opt/iredapd/settnigs.py, parameter MYNETWORKS = like below:
MYNETWORKS = ['192.168.0.10', '192.168.0.20', '192.168.0.30']
Notes:
This parameter doesn't exist by default, feel free to add it.
Parameter name is case SeNsItIvE.