What is an AAAA record (IPv6)?
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You've probably heard someone mention IPv6 and wondered if you actually need it for email. Here's the straightforward answer: an AAAA record does for IPv6 addresses what an A record does for IPv4 addresses. It tells the internet how to find your mail server using the newer address format.
How it works in plain terms: IPv4 addresses are 32-bit numbers (like 192.0.2.1). IPv6 addresses are 128-bit, written as eight groups of hexadecimal digits (like 2001:db8::1). Your AAAA record maps your domain to an IPv6 address. When someone's mail system is IPv6-only, it looks up your AAAA record to find your server. No AAAA record means they can't reach you.
Why it matters for email: Some networks, especially in certain regions and large organizations, are moving to IPv6-only infrastructure. Without AAAA records, your mail bounces for those senders. Additionally, IPv6 reputation is completely separate from IPv4. If you add a new IPv6 address without warming it up gradually, it might land in spam folders even if your IPv4 reputation is solid.
The practical next step: Check if your mail server already has IPv6 capability. If it does, ask your DNS provider to add an AAAA record pointing to it. Update your SPF record to include IPv6 if you're sending from that address. You can verify everything's set up correctly by running a quick DNS lookup.
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