No — app.constantcontact.com is IPv4 only.

Has an IPv4 address but no IPv6 (AAAA) record. IPv6-only visitors can't reach it directly.

D
IPv6 readiness
The website has no IPv6.
Website over IPv6
app.constantcontact.com has no AAAA record.		no
Mail servers (MX) have IPv6
No MX records, so mail goes to the domain's own address (implicit MX). It has no AAAA record.		no
Nameservers have IPv6
4 of 4 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up.
dns1.p01.nsone.net ✓dns2.p01.nsone.net ✓dns3.p01.nsone.net ✓dns4.p01.nsone.net ✓
yes

What's keeping app.constantcontact.com from an A

  1. app.constantcontact.com is an alias of app.constantcontact.com.cdn.cloudflare.net, which has no IPv6
    app.constantcontact.com is a CNAME, so it can't also have its own AAAA record. Ask whoever runs app.constantcontact.com.cdn.cloudflare.net to enable IPv6 there — or replace the alias with the A and AAAA records they give you. Why some hosts don't offer IPv6
  2. Mail servers without IPv6
    Your domain's mail goes to its own address, which has no AAAA record.

Check again

app.constantcontact.com  IPv4 only

Alias ofapp.constantcontact.com.cdn.cloudflare.net
A (IPv4)172.64.144.217
104.18.43.39
AAAA (IPv6)none

What this means

Visitors on IPv6-only networks (many mobile carriers) can still reach it, but only through a translator their carrier runs (NAT64). The site itself has no IPv6 address — and you can't make one up from the IPv4. Why some hosts don't offer it

Copy the evidence — a citation-ready record of this measurement

 Permanent link: aaaa.bot/r/B_Su9ZVOyb · How we measure

Checked 2026-11-02 12:43:05 UTC. Full DNS report: dns.pizza/domain/app.constantcontact.com · JSON: /api/v1/app.constantcontact.com