How is a.co?

Looks fine risk 0/100

Registered 17 years ago, on no blocklists we checked, valid HTTPS, the site answered 200 in 75 ms.

Why

02050100

finecarefulhigh risk

·Nothing in the checks added risk.

Rule-based: domain age, blocklists, TLS. A heuristic, not a guarantee.

The home page, rendered by how.is in a sandboxed browser. Nothing on it is clickable here.

Site

200

75 ms · ends at www.amazon.com

HTTPS

63 d

left on a Amazon certificate

Age

17 years

registered 2010-04-26

Blocklists

listings across 5 lists

Everything we looked at

DNS records3 record types

A	44.215.138.88 98.87.170.202 98.87.170.8
NS	pdns3.ultradns.org pdns4.ultradns.org pdns1.ultradns.net pdns6.ultradns.co.uk pdns2.ultradns.net pdns5.ultradns.info
TXT	v=spf1 -all

RegistrationMarkmonitor Inc.

registrar	Markmonitor Inc.
registered	2010-04-26
last changed	2026-04-13
owner	Amazon Technologies, Inc.
country	US
nameservers	pdns1.ultradns.net pdns2.ultradns.net pdns3.ultradns.org pdns4.ultradns.org pdns5.ultradns.info pdns6.ultradns.co.uk
status	clientUpdateProhibited clientTransferProhibited clientDeleteProhibited serverUpdateProhibited serverTransferProhibited serverDeleteProhibited

HTTPS certificate63 days left

valid	yes
issuer	Amazon
covers	www.amz.onl, a.co, www.a.co, amz.onl
protocol	TLSv1.3

issued 2026-06-20expires 2027-01-03

DNSSECinsecure

Domain is not signed with DNSSEC

. → co → a.co

Email authenticationfair

SPF	pass `v=spf1 -all`
DMARC	pass policy reject
DKIM	none of 1 common selectors

Whether mail claiming to be from this domain can be checked as genuine.

Security scoregrade B · 155/205

Basic Security

20/40missing: DNSSEC Enabled

Record Security

30/45missing: CAA Records, DKIM Presence

Advanced Security

10/25missing: Mail Server Configuration, IPv6 Support

Domain Reputation

50/50

Threat Detection

45/45missing: Domain Age Check

Blocklists0 listings · 11 lookups

SURBL MultidomainURIBL MultidomainSpamCop98.87.170.8Barracuda98.87.170.8UCEPROTECT Level 198.87.170.8SpamCop98.87.170.202Barracuda98.87.170.202UCEPROTECT Level 198.87.170.202SpamCop44.215.138.88Barracuda44.215.138.88UCEPROTECT Level 144.215.138.88

Green: clean. Red: listed. Grey: the list did not answer.

Ask it yourself

Agents get this as data. Bought through the API, the checks behind this page cost $0.070: profile $0.025 + trust $0.020 + screenshot $0.020 + site status $0.005.

curl "https://how.is/v1/domain/trust?domain=a.co" \ -H "Authorization: Bearer $HOWIS_KEY" # or pay per call in USDC (x402), no key: the 402 tells your agent the price curl -i "https://how.is/v1/domain/profile?domain=a.co"

MCP: add https://how.is/mcp to Claude, Codex or Cursor (one-line install) and ask for domain_trust on a.co. Reference: /llms.txt.

IPv6. Does a.co work over IPv6? See the live check on aaaa.bot — website, mail and nameservers, graded A–F.

Watch a.co. DNS read at the source every 5 minutes; certificate, blocklists and expiry every 6 hours. You get an email only when something changes.

Watch — $1 / 30 days