HOW.IS
?

How is slack.com?

Looks fine risk 0/100

Registered 34 years ago, on no blocklists we checked, valid HTTPS, the site answered 200 in 94 ms.

Why

02050100
finecarefulhigh risk
  • ·Nothing in the checks added risk.

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

How slack.com looks right now
The home page, rendered by how.is in a sandboxed browser. Nothing on it is clickable here.
Site
200
94 ms
HTTPS
70 d
left on a Let's Encrypt certificate
Age
34 years
registered 1992-10-21
Blocklists
0
listings across 5 lists

Everything we looked at

DNS records5 record types
A3.95.117.96
54.147.59.169
54.92.199.186
34.193.255.5
3.210.88.6
34.203.97.10
34.202.253.6
54.163.235.119
34.231.24.224
34.225.62.185
34.205.195.66
54.225.153.205
34.204.109.226
34.196.46.202
52.73.140.59
MX5 alt2.aspmx.l.google.com
10 aspmx2.googlemail.com
5 alt1.aspmx.l.google.com
10 aspmx3.googlemail.com
1 aspmx.l.google.com
NSns-606.awsdns-11.net
ns-1493.awsdns-58.org
ns-1901.awsdns-45.co.uk
ns-166.awsdns-20.com
TXT_0vidyxobp6x350odqhb4fo7fdxhmtq3
google-site-verification=efuXt5-oMr2CdNmVi6A9IO29KMKifpseD1qokxjWwcE
google-site-verification=KqX3Ngw0XEjz_0GVx_xwFFlCoO-bskhqU_lxv0Q77mk
google-site-verification=QvelFPjIOe3Vavw0q-aAVYaAPKmWCRjmmVVEAjgfjQc
google-site-verification=2PK67oVPNyEtS1avSlr3PhH5nSiFuticbQv_bT4pM2k
google-site-verification=v-LLB__IhraaI7ZzuE3jvRFIm2vERPLzWoepAEZJtKQ
spycloud-domain-verification=02e4c0be-cf43-44e4-beaf-4f99702ca632
OSSRH-54733
google-site-verification=o2grd1TLmZZ8GrqbhVIFtzO2MRLTtSUpBBIBYfhQVCQ
v=spf1 include:_spf.qualtrics.com include:mail.zendesk.com include:_spfextra.slack.com -all
hubspot-developer-verification=OTE4NzYxYTgtMDUwZi00MzgzLTk2YTUtZDAwNjBlODg1MWM0
google-site-verification=kB1KvgpSk9YkHsFmsj1VPI5YmDvfKctPxnplhGjyqtE
CAA{'type': 'CAA', 'issue': 'digicert.com; account=455b15ed272bed097725c6ea50e89921fc57379c5338a29305c05771df65fff1', 'critical': 0}
{'type': 'CAA', 'iodef': 'mailto:hostmaster@slack-corp.com', 'critical': 0}
{'type': 'CAA', 'issue': 'letsencrypt.org; accounturi=https://acme-v02.api.letsencrypt.org/acme/acct/1532134906', 'critical': 0}
RegistrationMarkMonitor Inc.
registrarMarkMonitor Inc.
registered1992-10-21
expires2027-10-20
last changed2025-09-18
ownerSlack Technologies, Inc.
nameserversns-1493.awsdns-58.org
ns-166.awsdns-20.com
ns-1901.awsdns-45.co.uk
ns-606.awsdns-11.net
statusclient delete prohibited
client transfer prohibited
client update prohibited
server delete prohibited
server transfer prohibited
server update prohibited
registered 1992-10-21expires 2027-10-20
HTTPS certificate70 days left
validyes
issuerLet's Encrypt
covers*.slack.com, slack.com
protocolTLSv1.3
issued 2026-10-07expires 2027-01-05
DNSSECsecure

Domain is properly signed — chain validated by an independent validating resolver

. → com → slack.com
Email authenticationgood
SPFpass v=spf1 include:_spf.qualtrics.com include:mail.zendesk.com include:_spfextra.slack.com -all
DMARCpass policy reject
DKIMnone of 20 common selectors

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

Security scoregrade B · 170/205
Basic Security
20/40missing: DNSSEC Enabled
Record Security
45/45missing: DKIM Presence
Advanced Security
20/25missing: IPv6 Support
Domain Reputation
50/50
Threat Detection
35/45missing: Fast-Flux Detection, Domain Age Check
Blocklists0 listings · 17 lookups
SURBL MultidomainURIBL MultidomainSpamCop3.95.117.96Barracuda3.95.117.96UCEPROTECT Level 13.95.117.96SpamCop34.225.62.185Barracuda34.225.62.185UCEPROTECT Level 134.225.62.185SpamCop54.147.59.169Barracuda54.147.59.169UCEPROTECT Level 154.147.59.169SpamCop3.210.88.6Barracuda3.210.88.6UCEPROTECT Level 13.210.88.6SpamCop54.92.199.186Barracuda54.92.199.186UCEPROTECT Level 154.92.199.186

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=slack.com" \ -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=slack.com"

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

Watch slack.com. 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