smtp.transip.nl publishes IPv6 but doesn't answer on it.

Has both IPv4 (A) and IPv6 (AAAA) addresses.

F
IPv6 readiness
Publishes IPv6 but doesn't answer on it — worse than having none.
Website over IPv6
smtp.transip.nl has an AAAA record, but nothing answered on ports 443 or 80. IPv6 visitors wait for a timeout before falling back to IPv4.
✗ 2a01:7c8:7c8::12 no answer✗ 2a01:7c8:7c8::29 no answer
broken
Mail servers (MX) have IPv6
No MX records, so mail goes to the domain's own address (implicit MX). It has an AAAA record.		yes
Nameservers have IPv6
3 of 3 nameservers checked have an AAAA record, so IPv6-only resolvers can look the domain up.
ns0.transip.net ✓ns1.transip.nl ✓ns2.transip.eu ✓
yes
 Load smtp.transip.nl over IPv6 from up to six other places — a second opinion.

What's keeping smtp.transip.nl from an A

  1. Fix or remove the AAAA record for smtp.transip.nl
    Something published an IPv6 address but nothing answers on it, so IPv6 visitors wait for a timeout first. Either make the server listen on IPv6 (and allow ports 443/80 through its firewall), or delete the AAAA record until it does.

Check again

smtp.transip.nl  Has IPv6

Alias ofrelay.transip.nl
A (IPv4)149.210.149.12
149.210.149.29
AAAA (IPv6)2a01:7c8:7c8::12
2a01:7c8:7c8::29

Browsers on dual-stack networks will usually pick IPv6 here (the "Happy Eyeballs" algorithm races both and prefers v6).

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

 Permanent link: aaaa.bot/r/u4fIHU9PaY · How we measure

Checked 2026-11-01 11:24:38 UTC. Full DNS report: dns.pizza/domain/smtp.transip.nl · JSON: /api/v1/smtp.transip.nl