October 9, 2025 · 8 min read
Missing or misconfigured PTR records are one of the leading causes of email landing in spam folders — or being rejected outright. Learn what reverse DNS is, why major mail providers check it, and what consequences ISPs face when PTR records are absent or incorrect.
rDNS
PTR records
Email deliverability
ISP
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December 3, 2025 · 7 min read
When you operate hundreds of IP blocks across multiple customers, managing PTR records manually becomes a liability. This guide covers the real-world challenges ISPs face at scale and how API-driven rDNS management changes the equation.
Bulk PTR
ISP management
Automation
API
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February 5, 2026 · 7 min read
IPv6 reverse DNS operates on a fundamentally different scale than IPv4 — a single /48 allocation contains 280 trillion addresses. This guide covers ip6.arpa zones, delegation from regional registries, and what automation is required to stay on top of it.
IPv6
Reverse DNS
ip6.arpa
RIPE
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