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Checking Your Domain SPF Record for Reliable Email Deliverability

Email remains the backbone of everyday communication for Australian small businesses, tradies booking jobs in regional Queensland, and large enterprises handling client invoices across Sydney and Melbourne. When a message lands in the recipient's junk folder, deals stall and trust erodes. A surprising number of those deliverability failures trace back to one small line of text in a domain's DNS settings: the SPF record. Getting it right is often the difference between a quote reaching a prospect's inbox and disappearing into a spam quarantine.

This guide walks through what an SPF record actually does, how to read it, and the simplest ways to verify it. Along the way, it touches on the local realities of running email under a .com.au or .au domain, where auDA's policies and ACMA's anti-scam rules shape what senders must do to stay out of trouble.

What an SPF Record Actually Does

SPF stands for Sender Policy Framework, and it lives as a DNS TXT record on a domain. In plain terms, it tells receiving mail servers which IP addresses are authorised to send email on behalf of that domain. When a message arrives at an inbox hosted by something like Microsoft 365 or Google Workspace, the receiving server checks the sending IP against the SPF record. A match means the message looks legitimate; a mismatch suggests spoofing or a misconfiguration, and the server often rejects or flags the message.

The SPF specification is deliberately simple. A record starts with v=spf1 and is followed by a series of mechanisms: ip4: and ip6: entries for specific addresses, include: statements that pull in third-party senders, a for the domain's own A record, and qualifiers like +, -, and ~ to indicate pass, fail, or soft fail. The record ends with an all mechanism, which decides what happens to anything not explicitly listed. A -all (hard fail) is the strictest setting, while a ~all is more forgiving. Many Australian businesses start with ~all while testing, then tighten the policy once they are confident no legitimate mail is being blocked.

Why Australian Senders Should Pay Attention

Local context matters. The Australian Communications and Media Authority has been steadily increasing pressure on SMS and email-based scams, and the Australian Cyber Security Centre regularly publishes guidance urging businesses to authenticate outbound mail. A misconfigured SPF record does not just hurt deliverability; it makes a domain a more attractive cover for phishing campaigns impersonating well-known Aussie brands such as banks, telcos, or retailers.

Domain policy also plays a role. auDA, which administers the .au namespace, requires that contact details on file be accurate and that domains remain in good standing. While SPF itself is not enforced by auDA, a domain that cannot reliably send mail because of broken authentication is harder to recover administratively. For businesses running their own mail through a local provider such as VentraIP or through an international service with a Sydney presence, the same SPF rules apply, and so do the same pitfalls.

Finding and Reading Your Current SPF Record

The fastest way to inspect a domain's SPF record is through a public DNS lookup. Tools such as the technology toolbox on CoderVortex will query authoritative name servers and return every TXT record tied to a domain. The relevant entry usually appears under the bare hostname, for example example.com.au rather than www.example.com.au, and it begins with the v=spf1 string.

Once the record is in front of you, reading it is straightforward. Look for the number of include statements first. SPF has a hard limit of ten DNS lookups per check, and going over that limit causes some receiving servers to treat the message as suspicious. Common offenders include marketing platforms, transactional services, and old ESP records that were never removed when a provider changed. A typical small-business record might look like v=spf1 include:_spf.google.com include:mailgun.org ip4:203.0.113.5 -all, which keeps things tidy and explicit.

Pitfalls That Often Break Deliverability

Several recurring problems show up in Australian SPF setups. The first is exceeding the lookup limit. Adding a new include for every new marketing tool quickly pushes the count past ten, especially for shops juggling a newsletter platform, a transactional sender, and a CRM. The second is leaving an old include behind after migrating from one provider to another; if the old provider's domain expires or returns an empty record, valid mail can be silently affected.

The third is the wrong all qualifier. A -all is correct for domains that know exactly who sends on their behalf, but it is punishing for anyone still in the middle of a transition. A ?all neutral setting can mask underlying issues, which is why most operators either commit to ~all while cleaning things up or move straight to -all once the record is stable. Finally, typos and missing colons trip up records more often than expected. A single space in the wrong place can make a record invalid and turn a normally reliable sender into a permanent junk-folder resident.

Tightening Things Up With the Right DNS Setup

Once the record is correct, keeping it healthy is mostly a matter of process. Update the SPF entry whenever an email provider changes, retire any include that is no longer needed, and document what each mechanism is for. A short internal note attached to the DNS zone saves hours the next time someone asks why a particular service is listed.

For businesses that want a simpler way to manage DNS and additional protections like DDoS mitigation, switching to a managed DNS provider can help. Cloudflare, for instance, handles SPF, DKIM, and DMARC records through a clean interface and adds layers of security on top. The walkthrough at the Cloudflare DNS guide on CoderVortex covers the practical steps for moving a domain over while keeping mail flowing across AEST and AEDT time zones.

Practical Recommendations for a Healthy SPF Setup