usc.edu SPF Record Checker

//01

SPF Record Check for usc.edu

The SPF record for usc.edu defines exactly which IP addresses and mail services are permitted to send email using @usc.edu addresses. When a receiving mail server gets an email claiming to be from usc.edu, it checks this SPF record to verify that the sending server is authorized.

If usc.edu's SPF record is configured correctly, it protects against email spoofing — preventing unauthorized parties from sending emails that appear to come from usc.edu. A missing or misconfigured SPF record can lead to delivery problems and makes the domain vulnerable to phishing attacks.

This SPF record checker breaks down each component of usc.edu's SPF record, showing which IP ranges and services are included and whether the policy ends with a hard fail (-all), soft fail (~all), or neutral (?all) for unauthorized senders.

//02

What Is SPF?

SPF (Sender Policy Framework), defined in RFC 7208, works by publishing a DNS TXT record that lists the IP addresses and domains allowed to send email for usc.edu. Receiving mail servers check this record to verify that incoming email actually comes from an authorized source.

Without SPF, anyone on the internet can forge the "From" address in an email to impersonate usc.edu. SPF helps prevent this by giving receiving servers a way to verify that the sending server's IP address is authorized by usc.edu's domain administrators.

//03

SPF Syntax Explained

An SPF record starts with "v=spf1" and contains one or more mechanisms: "ip4:" and "ip6:" specify allowed IP ranges, "include:" references another domain's SPF record, "a" allows the domain's own A record IPs, "mx" allows IPs from MX records, and "all" is the catch-all at the end.

Qualifiers modify how each mechanism is evaluated: "+" means pass (default if omitted), "-" means hard fail, "~" means soft fail, and "?" means neutral. A record ending in "-all" strictly rejects unauthorized senders, while "~all" marks them as suspicious but doesn't outright reject them. Best practice for usc.edu is to use "-all" once all legitimate sending sources are accounted for.

//04

SPF Best Practices

Keep the SPF record under the 10 DNS lookup limit — each "include:", "a", "mx", and "redirect" mechanism counts toward this limit. Exceeding it causes a "permerror" that can result in all email from usc.edu failing SPF checks.

Use "-all" instead of "~all" once you're confident all legitimate senders for usc.edu are included. Regularly audit the "include:" entries to remove services usc.edu no longer uses. If the record is approaching the 10-lookup limit, consider "flattening" includes into explicit IP ranges.

Monitor SPF alignment with DMARC reports. DMARC aggregate reports will show you if legitimate email from usc.edu is failing SPF checks, which helps identify missing authorized senders.

//05

Frequently Asked Questions

Does usc.edu have SPF? — The SPF analysis for usc.edu shows whether the domain has a published SPF record and details its contents. If no SPF record is found, usc.edu has not configured email sender authorization.

What is usc.edu's SPF policy? — The SPF policy is determined by the final mechanism in the record. "-all" means hard fail (reject unauthorized senders), "~all" means soft fail (flag but don't reject), and "?all" means neutral (no policy).

Is usc.edu protected from email spoofing? — SPF alone provides partial protection. Full email spoofing protection for usc.edu requires SPF combined with DKIM and a DMARC policy set to "quarantine" or "reject". Check usc.edu's DMARC page for the full picture.

Why is email from usc.edu going to spam? — If SPF checks are failing, email from usc.edu may be flagged as suspicious. Verify that all sending servers and services are included in the SPF record.