`cst-learning.slack.com`

DNSSEC	⚠️ Not signed
A	18.230.171.141^{🇧🇷 Amazon18.230.0.0/16 EC2 GRU prefix}
		PTR	`ec2-18-230-171-141.sa-east-1.compute.amazonaws.com`
A	54.94.183.148^{🇧🇷 Amazon54.94.128.0/18 EC2 GRU prefix}
MX	`inbound-smtp.us-east-1.amazonaws.com` ⭐
		A	3.211.210.226^{🇺🇸 Amazon3.208.0.0/12 EC2 IAD prefix}
			PTR	`ec2-3-211-210-226.compute-1.amazonaws.com`
		A	44.206.9.87^{🇺🇸 Amazon44.192.0.0/11 EC2 IAD prefix}
			PTR	`ec2-44-206-9-87.compute-1.amazonaws.com`
		A	44.210.166.32^{🇺🇸 Amazon44.192.0.0/11 EC2 IAD prefix}
			PTR	`ec2-44-210-166-32.compute-1.amazonaws.com`
		A	54.164.173.191^{🇺🇸 Amazon54.164.0.0/15 EC2 IAD prefix}
			PTR	`ec2-54-164-173-191.compute-1.amazonaws.com`
		A	54.197.5.236^{🇺🇸 Amazon54.196.0.0/15 EC2 IAD 54.196.0.0/15}
			PTR	`ec2-54-197-5-236.compute-1.amazonaws.com`
TXT	`v=spf1 -all`

`slack.com`

	DNSSEC	🔒 Signed (DS record present)
	A	18.230.171.141^{🇧🇷 Amazon18.230.0.0/16 EC2 GRU prefix}
	A	54.94.183.148^{🇧🇷 Amazon54.94.128.0/18 EC2 GRU prefix}
	NS	`ns-1493.awsdns-58.org` ⭐
	NS	`ns-166.awsdns-20.com`
	NS	`ns-1901.awsdns-45.co.uk`
	NS	`ns-606.awsdns-11.net`
	MX	`aspmx.l.google.com` ⭐
	MX	`alt1.aspmx.l.google.com`⁽⁵⁾
	MX	`alt2.aspmx.l.google.com`⁽⁵⁾
	MX	`aspmx2.googlemail.com`⁽¹⁰⁾
	MX	`aspmx3.googlemail.com`⁽¹⁰⁾
	TXT	`OSSRH-54733`
	TXT	`_0vidyxobp6x350odqhb4fo7fdxhmtq3`
	TXT	`google-site-verification=2PK67oVPNyEtS1avSlr3PhH5nSiFuticbQv_bT4pM2k`
	TXT	`google-site-verification=KqX3Ngw0XEjz_0GVx_xwFFlCoO-bskhqU_lxv0Q77mk`
	TXT	`google-site-verification=QvelFPjIOe3Vavw0q-aAVYaAPKmWCRjmmVVEAjgfjQc`
	TXT	`google-site-verification=efuXt5-oMr2CdNmVi6A9IO29KMKifpseD1qokxjWwcE`
	TXT	`google-site-verification=kB1KvgpSk9YkHsFmsj1VPI5YmDvfKctPxnplhGjyqtE`
	TXT	`google-site-verification=o2grd1TLmZZ8GrqbhVIFtzO2MRLTtSUpBBIBYfhQVCQ`
	TXT	`google-site-verification=v-LLB__IhraaI7ZzuE3jvRFIm2vERPLzWoepAEZJtKQ`
	TXT	`hubspot-developer-verification=OTE4NzYxYTgtMDUwZi00MzgzLTk2YTUtZDAwNjBlODg1MWM0`
	TXT	`spycloud-domain-verification=02e4c0be-cf43-44e4-beaf-4f99702ca632`
	TXT	`v=spf1 include:_spf.qualtrics.com include:mail.zendesk.com include:_spfextra....`
	SOA	`ns-1493.awsdns-58.org`awsdns-hostmaster@amazon.com serial=1

WOT: SAFE (93/100)
rank #425 globally
rank #273 in the tld
This domain, slack.com, is the official website for Slack, a business communication platform. Slack offers a variety of features such as direct messaging, group chats, and topic-specific channels to help teams communicate and collaborate more effectively. In addition to its communication features, it also allows integration with other services like Google Drive, Trello, and Dropbox.WOT: SAFE (93/100)
📈 Tranco rank: #320

Slack is a business communication platform founded in 2013 and acquired by Salesforce in 2021 for $27.7 billion. With over 18 million daily active users, Slack has become essential collaboration infrastructure for businesses, replacing email for many internal communications.

Slack offers real-time messaging, channels for organized discussions, file sharing, integrations with thousands of apps, and Slack Huddles for quick audio conversations. The platform pioneered many features now standard in business chat tools.

Slack's infrastructure handles millions of concurrent connections with strict real-time requirements. The platform processes billions of messages daily, with significant infrastructure for search and file storage.

DNS for slack.com uses Amazon Route 53 with global distribution. The platform's enterprise customers require high availability and security.

DNS History

21 records (3 active, 18 former)

●MXinbound-smtp.us-east-1.amazonaws.com2026-03-07 → 2026-03-31 · 3 obs

○ 2017-03-22 03:13:10
● 2026-03-07 01:11:54
● 2026-03-31 10:33:00

○MXmxa.mailgun.org2017-03-22 → 2017-03-22 · 3 obs

● 2017-03-22 03:13:10
○ 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○MXmxb.mailgun.org2017-03-22 → 2017-03-22 · 3 obs

● 2017-03-22 03:13:10
○ 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A18.159.197.2252026-03-07 → 2026-03-07 · 3 obs

○ 2017-03-22 03:13:10
● 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

●A18.230.171.1412026-03-31 → 2026-03-31 · 2 obs

○ 2026-03-07 01:11:54
● 2026-03-31 10:33:00

○A3.68.124.1682026-03-07 → 2026-03-07 · 3 obs

○ 2017-03-22 03:13:10
● 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A3.68.124.952026-03-07 → 2026-03-07 · 3 obs

○ 2017-03-22 03:13:10
● 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A3.68.170.1532026-03-07 → 2026-03-07 · 3 obs

○ 2017-03-22 03:13:10
● 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A3.68.175.982026-03-07 → 2026-03-07 · 3 obs

○ 2017-03-22 03:13:10
● 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A35.81.85.2512026-03-07 → 2026-03-31 · 2 obs

○ 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A35.82.91.1932026-03-07 → 2026-03-31 · 2 obs

○ 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A44.234.235.932026-03-07 → 2026-03-31 · 2 obs

○ 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A44.237.180.1722026-03-07 → 2026-03-31 · 2 obs

○ 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A52.29.238.2122026-03-07 → 2026-03-07 · 3 obs

○ 2017-03-22 03:13:10
● 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A52.89.90.672026-03-07 → 2026-03-31 · 2 obs

○ 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A54.188.33.222026-03-07 → 2026-03-31 · 2 obs

○ 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A54.230.143.1942017-03-22 → 2017-03-22 · 3 obs

● 2017-03-22 03:13:10
○ 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A54.245.50.2452026-03-07 → 2026-03-31 · 2 obs

○ 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A54.70.179.162026-03-07 → 2026-03-31 · 2 obs

○ 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

○A54.71.95.1932026-03-07 → 2026-03-31 · 2 obs

○ 2026-03-07 01:11:54
○ 2026-03-31 10:33:00

●A54.94.183.1482026-03-31 → 2026-03-31 · 2 obs

○ 2026-03-07 01:11:54
● 2026-03-31 10:33:00

🔍 DNS Trace

📋 Delegation Chain

Zone	Nameservers	Glue
com	f.gtld-servers.net, a.gtld-servers.net, j.gtld-servers.net, d.gtld-servers.net...	-
slack.com	ns-166.awsdns-20.com, ns-606.awsdns-11.net, ns-1901.awsdns-45.co.uk, ns-1493.awsdns-58.org	1 record

✅ Authoritative Response

Server:205.251.197.213

NS records: ns-166.awsdns-20.com, ns-606.awsdns-11.net, ns-1901.awsdns-45.co.uk, ns-1493.awsdns-58.org

🔒 DNSSEC Status

🔐 Secure (DNSSEC validated)

Chain of trust verified from root to domain

⏱️ Timing

Total: 474ms | Queries: -

📄 Records

Type	Count	Sample Data
A	2	`18.230.171.141, 54.94.183.148`
MX	1	`inbound-smtp.us-east-1.amazonaws.com (pr`
TXT	1	`v=spf1 -all`

📌 Glue Records Collected

Total: 1

Out-of-bailiwick: 1 (ns-166.awsdns-20.com)

Analysis

IP Addresses

cst-learning.slack.com points to two IP numbers: 18.230.171.141 and 54.94.183.148.

Other host names, for instance dentalkartgroup.slack.com, sudofim.slack.com, kuehnenagel.slack.com, puzhevich.slack.com and ec2-18-230-171-141.sa-east-1.compute.amazonaws.com share IP numbers with cst-learning.slack.com.

Mail Servers

cst-learning.slack.com is served by a single mail server, inbound-smtp.us-east-1.amazonaws.com.

cst-learning.slack.com uses the same mail server setup as other domains such as ces.edu.gh, contentsbiz.slack.com, closbelmontico.slack.com, planlogweb.com.br and mosaikfamily.slack.com.

cst-learning.slack.com shares some mail servers with other domains, including tweddle.tech, au-eboq.atlassian.net, apgasif.org, thisisblaze.com and researchcalgary.atlassian.net.

These mail servers are often used alongside the mail servers inbound-smtp.us-west-2.amazonaws.com.

Host inbound-smtp.us-east-1.amazonaws.com resolves to five IP numbers: 3.211.210.226, 44.206.9.87, 44.210.166.32, 54.164.173.191 and 54.197.5.236.

cst-learning.slack.com - robtex.com