No — smtp.uchicago.edu 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
smtp.uchicago.edu 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
No nameserver has an AAAA record — an IPv6-only resolver can't reach this domain's DNS.
ucns1.uchicago.yale.edu ✗ucns1.uchicago.uiowa.edu ✗ucns3.uchicago.edu ✗ucns4.uchicago.edu ✗
no

What's keeping smtp.uchicago.edu from an A

  1. smtp.uchicago.edu is an alias of smtp.wip.uchicago.edu, which has no IPv6
    smtp.uchicago.edu is a CNAME, so it can't also have its own AAAA record. Ask whoever runs smtp.wip.uchicago.edu 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.
  3. Nameservers without IPv6
    ucns1.uchicago.yale.edu, ucns1.uchicago.uiowa.edu, ucns3.uchicago.edu, ucns4.uchicago.edu all have no AAAA record, so a resolver that only speaks IPv6 can't look your domain up. Most DNS providers offer IPv6 nameservers; ask yours, or move DNS to one that does.

Check again

smtp.uchicago.edu  IPv4 only

Alias ofsmtp.wip.uchicago.edu
A (IPv4)128.135.176.45
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/DIeE9ChZbV · How we measure

Checked 2026-11-01 07:19:48 UTC. Full DNS report: dns.pizza/domain/smtp.uchicago.edu · JSON: /api/v1/smtp.uchicago.edu