Domain Intelligence
Last Updated:
Csx.com
Safe to Send
Csx.com is operated by CSX Transportation. The domain runs 1 mail exchange and SMTP is responsive, with all three authentication standards in force.
Safe to Send
RISK
15
/100
Low
Verify Mailbox
Verify @csx.com emails
Live SMTP handshake against csx.com mail servers. No email is sent. 10 free per day, no signup.
Trusted by 400,000+ senders
4.9/5
From 8,500+ verified reviews
Disposable detection is the strongest I've tested. We were drowning in fake signups before integration. Fraudulent account creation dropped roughly 80% in the first 10 days. Risk score on the lookup pages helps our analysts triage faster too. Elena Reyes · Trust & Safety, Fintech
SOC 2 Type II
GDPR
CCPA
99.7% Accuracy
Disposable
No
Persistent addresses, not throwaway
SMTP Live
Yes
Mail server responds to SMTP handshake
MX Records
1
Mail exchangers
Mail Exchange (MX) Records for csx.com Mail Exchange records. They tell other mail servers which hosts are responsible for receiving email at this domain, in priority order. Lower priority numbers are tried first.
#0
csx-com.mail.protection.outlook.com 52.101.50.7
Reachable
SMTP Handshake
Simple Mail Transfer Protocol. We open a live SMTP connection to the primary MX and read the greeting banner. A response confirms the mail server is alive and accepting connections.
Responsive
BANNER220 BN1PEPF00004680.mail.protection.outlook.com Microsoft ESMTP MAIL Service ready at Tue, 12 May 2026 18:10:11 +0000 [08DEADB89A712BB0]
Primary mail server accepted SMTP connection and returned a banner during the live audit.
csx.com Email Authentication SPF · DKIM · DMARC
SPF
Sender Policy Framework. A DNS record listing which servers are allowed to send mail for this domain. Receivers reject or flag mail from unauthorized servers.
Pass
TXTv=spf1 mx ip4:216.231.210.162/32 ip4:216.231.210.163/32 ip4:216.231.208.128/32 ip4:216.231.208.151/32 ip4:172.210.45.246/32 ip4:172.178.103.202/32 ip4:208.73.5.26/32 include:spf.protection.outlook.com include:spf-include.csx.com -all
Authorized senders are defined and pass SPF policy.
DKIM
DomainKeys Identified Mail. The sending server cryptographically signs outbound mail with a private key, and receivers verify the signature using a public key in DNS.
Pass
SELECTORDetected via standard selectors
A DKIM signature was detected. Outbound mail from this domain can be cryptographically verified.
DMARC
Domain-based Message Authentication, Reporting & Conformance. Tells receivers what to do when SPF or DKIM checks fail: none, quarantine, or reject.
None
TXTv=DMARC1; p=none; fo=1; rua=mailto:DMARC_Forensic@csx.com; ruf=mailto:DMARC_Forensic@csx.com
Monitoring only. Receivers take no action when SPF or DKIM fails.
csx.com Domain Registration WHOIS · Nameservers · Registrar
RegistrarCSC Corporate Domains, Inc.
IANA ID299
RegisteredMay 16, 1995
Last UpdatedApril 21, 2026
ExpiresMay 18, 2026
Age30 years
TLD.com
Authoritative Nameservers (4)
- ns-965.awsdns-56.net
- ns-1898.awsdns-45.co.uk
- ns-1218.awsdns-24.org
- ns-268.awsdns-33.com
Registrant
CSX Technology
FL, UNITED STATES
About this Domain
About csx.com
CSX Transportation (csx.com) is a major freight railroad in the eastern United States, headquartered in Jacksonville, Florida. CSX operates approximately 20,000 miles of track across 23 states, transporting coal, intermodal containers, chemicals, agricultural products, and automotive goods. The company is one of the largest railroads in North America.
CSX implements enterprise email authentication on the csx.com domain with SPF, DKIM, and DMARC enforcement. As critical transportation infrastructure, CSX maintains robust email security to protect shipping logistics, hazardous materials documentation, and railway operations communications.
SMTP verification of csx.com addresses returns definitive responses for valid and invalid mailboxes. The domain does not function as catch-all. CSX's enterprise mail infrastructure implements rate limiting on inbound SMTP connections.
For partners communicating with CSX employees, proper sender authentication improves deliverability. CSX's corporate email filters enforce SPF, DKIM, and DMARC validation. Authentication compliance ensures reliable inbox delivery to csx.com addresses.
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Common Questions About csx.com
Is csx.com a disposable or temporary email provider?
No. csx.com is not a disposable email provider. It is classified as Corporate Email operated by CSX Transportation and addresses on csx.com are persistent rather than throwaway. Mail sent to a valid csx.com mailbox reaches a real recipient.
How do I verify if a csx.com email address is valid?
The fastest way to verify a csx.com email address is to use our free email checker. Enter any @csx.com mailbox at the top of this page and our system performs a real-time SMTP handshake against csx.com's mail servers, confirming whether the mailbox exists, is reachable, and is safe to send to. No email is ever delivered during the check.
Can I check if a csx.com email exists without sending a message?
Yes. Our real-time email verification API connects directly to csx.com's mail server, opens an SMTP session, and queries the mailbox using the RCPT TO command without ever transmitting an actual email. The server's response confirms whether the csx.com mailbox is valid, full, or non-existent. The recipient never receives anything and never sees the check.
What are the MX records for csx.com?
csx.com currently publishes 1 mail exchange (MX) record. The primary MX is csx-com.mail.protection.outlook.com, which is the first server contacted when other mail systems try to deliver email to a csx.com address. The full list with priorities and IP addresses is in the MX Records panel above. MX records tell sending servers where to route email for csx.com.
Does csx.com use SPF, DKIM, and DMARC email authentication?
csx.com enforces all three email authentication standards: SPF, DKIM, and DMARC (policy: none). This is the gold-standard configuration. It means receivers can verify that mail claiming to come from @csx.com is genuine, and csx.com's DMARC policy of 'none' instructs receivers how to handle messages that fail those checks.
Why do emails to csx.com bounce or get blocked?
Bounces from csx.com usually fall into three buckets: the mailbox doesn't exist (5xx user unknown), the inbox is full, or your sending domain isn't authenticated to csx.com's satisfaction. The fastest fix is to run each address through a free email verifier before you send, and to make sure your own SPF, DKIM, and DMARC are configured correctly so csx.com's receivers trust you.
How can I verify a large list of csx.com email addresses?
Our bulk email verifier accepts CSV or TXT uploads with thousands or millions of csx.com addresses (or any mix of domains). Every address goes through 30+ checks including SMTP existence, csx.com catch-all detection, role-account detection, and disposable-domain matching. Results typically come back within minutes and previously-failed addresses on your blacklist are reprocessed for free. For continuous high-volume needs, see our unlimited email verification API.
Is it safe to accept signups from csx.com email addresses?
Yes, with normal hygiene. csx.com is a legitimate email service and signups from @csx.com behave like any other real user. Pipe each address through a real-time email verifier API at the moment of signup to catch typos and dead mailboxes, but there is no need to block csx.com by default.
What email format does csx.com use for usernames?
Most csx.com mailboxes follow common patterns like first.last@csx.com, firstinitiallast@csx.com, or first@csx.com, but the actual local-part rules depend on CSX Transportation. The only reliable way to confirm whether a specific @csx.com address exists is to run it through a free email verification tool. Guessing patterns will produce a high bounce rate and damage your sender reputation.
How is the csx.com risk score calculated?
The 0-to-100 risk score for csx.com combines disposable-domain classification, mail-server reachability, MX record presence and depth, SPF / DKIM / DMARC enforcement, DMARC policy strength, SMTP banner response, and domain age. Lower scores mean safer to send to. Disposable domains are pinned at the high end of the scale. The csx.com score is recomputed on every audit so it always reflects the live state of the domain.
Is csx.com a valid corporate email domain?
Yes, csx.com is the official corporate email domain for CSX Transportation. It is used for internal business communications and is not available for public registration.
Is csx.com a disposable or temporary email provider?
No, csx.com is a corporate email domain belonging to CSX Transportation, used exclusively by employees and authorized personnel.
What mail server does csx.com use?
csx.com uses enterprise-grade mail infrastructure. Check the MX records section above for specific mail server details.
Can I send marketing emails to csx.com addresses?
B2B marketing to csx.com requires proper consent. Corporate domains may use catch-all configurations, so verify individual addresses before sending.
How do I verify an email address at csx.com?
Corporate domains like csx.com may use catch-all configurations. Use BulkEmailChecker's advanced verification to detect catch-all behavior.