Domain Intelligence
Last Updated:
F5.com
Safe to Send
F5.com is operated by F5 Networks. The domain runs 2 mail exchanges and SMTP is responsive, with all three authentication standards in force.
Safe to Send
RISK
10
/100
Low
Verify Mailbox
Verify @f5.com emails
Live SMTP handshake against f5.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
The risk score saves my team probably an hour a day in manual prospect research. We sort outreach lists by it and skip anything in the high-risk band. Bounce rate is the lowest it's ever been. Lisa Fonseca · SDR Team Lead
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
2
Mail exchangers
Mail Exchange (MX) Records for f5.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.
#10
mx1.hc5801-97.iphmx.com 139.138.58.65
Reachable
#10
mx2.hc5801-97.iphmx.com 139.138.58.65
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 esa.hc5801-97.iphmx.com ESMTP
Primary mail server accepted SMTP connection and returned a banner during the live audit.
f5.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 ip4:104.219.104.72 ip4:104.219.106.65 ip4:104.219.105.72 ip4:104.219.107.65 exists:%{i}.spf.hc5801-97.iphmx.com include:spf.protection.outlook.com include:mktomail.com include:_spf.salesforce.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.
Reject
TXTv=DMARC1; p=reject; fo=1; ri=3600; rua=mailto:dmarc_agg@vali.email; ruf=mailto:dmarc_report@f5.com
Strict policy. Receivers are instructed to reject any mail that fails SPF or DKIM. The strongest available setting.
f5.com Domain Registration WHOIS · Nameservers · Registrar
RegistrarCSC Corporate Domains, Inc.
IANA ID299
RegisteredMay 30, 1996
Last UpdatedApril 19, 2026
ExpiresMay 30, 2026
Age29 years
TLD.com
Authoritative Nameservers (4)
- PDNS130.F5.COM
- PDNS150.F5.COM
- PDNS151.F5.COM
- PDNS131.F5.COM
Registrant
F5, Inc.
WA, UNITED STATES
About this Domain
About f5.com
F5 Networks (f5.com) is a technology company headquartered in Seattle, Washington. F5 provides application delivery networking, application security, multi-cloud management, and API security solutions. The company's products, including the BIG-IP platform and NGINX, are used by organizations to ensure application availability, performance, and security.
F5 implements comprehensive email authentication on the f5.com domain with SPF, DKIM, and DMARC enforcement. As a network security and application delivery company, F5 applies strong security practices to its own domain, demonstrating the protection standards it helps customers achieve.
Email verification against f5.com returns definitive responses for valid and invalid mailboxes. The domain does not operate as catch-all. F5's mail infrastructure implements rate limiting and security monitoring on inbound SMTP connections.
For partners communicating with F5 employees, proper sender authentication is essential. Network security companies enforce strict email filtering. Full SPF, DKIM, and DMARC compliance ensures reliable inbox delivery to f5.com addresses.
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Common Questions About f5.com
Is f5.com a disposable or temporary email provider?
No. f5.com is not a disposable email provider. It is classified as Corporate Email operated by F5 Networks and addresses on f5.com are persistent rather than throwaway. Mail sent to a valid f5.com mailbox reaches a real recipient.
How do I verify if a f5.com email address is valid?
The fastest way to verify a f5.com email address is to use our free email checker. Enter any @f5.com mailbox at the top of this page and our system performs a real-time SMTP handshake against f5.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 f5.com email exists without sending a message?
Yes. Our real-time email verification API connects directly to f5.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 f5.com mailbox is valid, full, or non-existent. The recipient never receives anything and never sees the check.
What are the MX records for f5.com?
f5.com currently publishes 2 mail exchange (MX) records. The primary MX is mx1.hc5801-97.iphmx.com, which is the first server contacted when other mail systems try to deliver email to a f5.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 f5.com.
Does f5.com use SPF, DKIM, and DMARC email authentication?
f5.com enforces all three email authentication standards: SPF, DKIM, and DMARC (policy: reject). This is the gold-standard configuration. It means receivers can verify that mail claiming to come from @f5.com is genuine, and f5.com's DMARC policy of 'reject' instructs receivers how to handle messages that fail those checks.
Why do emails to f5.com bounce or get blocked?
Bounces from f5.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 f5.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 f5.com's receivers trust you.
How can I verify a large list of f5.com email addresses?
Our bulk email verifier accepts CSV or TXT uploads with thousands or millions of f5.com addresses (or any mix of domains). Every address goes through 30+ checks including SMTP existence, f5.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 f5.com email addresses?
Yes, with normal hygiene. f5.com is a legitimate email service and signups from @f5.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 f5.com by default.
What email format does f5.com use for usernames?
Most f5.com mailboxes follow common patterns like first.last@f5.com, firstinitiallast@f5.com, or first@f5.com, but the actual local-part rules depend on F5 Networks. The only reliable way to confirm whether a specific @f5.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 f5.com risk score calculated?
The 0-to-100 risk score for f5.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 f5.com score is recomputed on every audit so it always reflects the live state of the domain.
Is f5.com a valid email domain?
Yes, f5.com is the official corporate email domain for F5 Networks. It is used for internal business communications.
Is f5.com a disposable or temporary email provider?
No, f5.com is a corporate email domain belonging to F5 Networks, used exclusively by employees and authorized personnel.
What mail server does f5.com use?
f5.com uses enterprise-grade mail infrastructure. Check the MX records section for specific mail server details.
Can I send marketing emails to f5.com addresses?
B2B marketing to f5.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 f5.com?
Corporate domains like f5.com may use catch-all configurations that accept all addresses. Use BulkEmailChecker advanced verification to detect catch-all behavior and validate individual mailboxes.