How to protect IP using SMTP and without an IP attribute?
To protect IP when using SMTP without needing an IP attribute, consider configuring SPF, DKIM, and DMARC records to prevent IP-based spoofing and protect email authenticity.
DNS responses often present a challenge due to their complexity. Understanding the response codes like NOERROR, NXDOMAIN, SERVFAIL, and REFUSED is crucial for diagnosis.