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Definition
An email deliverability audit is a structured review of the technical, reputational and configuration factors that affect whether business emails are accepted, rejected, quarantined or filtered into spam. It usually checks DNS records, email authentication, sending infrastructure, domain reputation, mailbox setup, website form delivery and common spam triggers.
An audit can improve the conditions for better delivery, but it cannot guarantee inbox placement. Spam filtering also depends on recipient mail systems, user behaviour, email content, sender history and third-party provider rules.
Key Takeaways
- An email deliverability audit checks whether your domain, DNS records and sending platforms are correctly configured to send trusted business email.
- The most important technical checks usually include SPF, DKIM and DMARC, along with MX records, DNS consistency, sender reputation and spam filtering behaviour.
- Deliverability problems can affect invoices, enquiries, website form notifications, client communication and trust, so they should be treated as a business continuity issue, not just an email app problem.
Quick Explanation
What an Email Deliverability Audit Looks For
Deliverability Is Not the Same as Guaranteed Inbox Placement
Key Email Deliverability Terms
These terms appear often during an email deliverability audit. Understanding them makes it easier to see why email problems are rarely caused by one setting alone.
- SPF
- Sender Policy Framework is a DNS record that lists which servers or platforms are authorised to send email for your domain.
- DKIM
- DomainKeys Identified Mail adds a digital signature to outgoing emails so receiving servers can check that the message was not altered after being sent.
- DMARC
- Domain-based Message Authentication, Reporting and Conformance connects SPF and DKIM to a policy that tells receiving servers what to do when a message fails authentication.
Audit Process
How an Email Deliverability Audit Usually Works
The exact process depends on the domain, email provider and connected systems, but most audits follow a logical sequence. The aim is to understand what sends email, how it is authenticated and where failures may occur.
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Map the Sending Sources
The audit identifies every system that sends email using the business domain. This may include Microsoft 365, website forms, CRM software, booking systems, accounting platforms and marketing tools.
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Check DNS and Authentication Records
The domain is reviewed for MX, SPF, DKIM and DMARC records. The audit checks whether records exist, whether they are valid, whether there are duplicates and whether they match the platforms actually sending email.
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Review Failures, Reputation and Risk
The audit looks for symptoms such as rejected messages, spam placement, authentication failures, blacklisting, inconsistent sending patterns and website form delivery problems. Findings are then prioritised by business impact and technical risk.
Technical Checks
SPF, DKIM and DMARC Checks
Example Email Authentication Records
The following records are illustrative only. Real values depend on your domain, email provider and connected platforms. For example, Microsoft 365, website forms and third-party tools may each require different DNS entries.
example.com. TXT "v=spf1 include:spf.protection.outlook.com -all"
selector1._domainkey.example.com. CNAME selector1-example-com._domainkey.example.onmicrosoft.com.
_dmarc.example.com. TXT "v=DMARC1; p=none; rua=mailto:[email protected]; adkim=s; aspf=s"Do not copy these records into a live domain without checking your actual provider requirements.
Business Impact
Why Deliverability Problems Matter for Business Email
Common Issues an Email Deliverability Audit Can Diagnose
The symptoms may look simple, but the cause is often hidden in DNS, authentication, provider settings or sending behaviour.
Emails are landing in spam
Likely cause
The domain may have missing or failing authentication, poor sender reputation, spam-like content, inconsistent sending patterns or issues with the recipient's filtering rules.
Solution
Check SPF, DKIM and DMARC first, then review sending sources, message content, domain reputation and any recent changes to email platforms or DNS.
Website form notifications are not arriving
Likely cause
The website may be sending mail from a server that is not authorised in SPF, or the form may be using a sender address that does not align with the domain.
Solution
Configure the website to send through an authenticated mail service where appropriate, then test form delivery, headers and recipient filtering.
Some emails work but others fail
Likely cause
Different systems may be sending mail in different ways. Microsoft 365 mailboxes may pass authentication while a CRM, invoicing platform or website form fails.
Solution
List every sending platform, confirm each one is authorised and check whether each source is signing messages correctly with DKIM where supported.
Common Email Deliverability Mistakes
Most deliverability problems are not caused by one dramatic failure. They often come from small configuration mistakes that build up over time as new tools and providers are added.
Adding a new platform without updating SPF or DKIM
Do this instead
Every platform that sends email for your domain should be checked before it goes live. If it needs authentication records, those records should be added and tested.
Publishing multiple SPF records on one domain
Do this instead
A domain should normally have one SPF record that includes all authorised senders. Multiple SPF records can cause SPF validation to fail.
Turning on a strict DMARC policy too early
Do this instead
DMARC enforcement should usually follow a review of all sending sources. Moving to quarantine or reject before legitimate systems are aligned can block valid business email.
Technical Checks vs Sending Behaviour Checks
An email deliverability audit should not stop at DNS records. Technical configuration matters, but receiving servers also look at sender history, message patterns and user engagement signals.
| Audit Area | Technical Configuration | Sending Behaviour |
|---|---|---|
| Main focus | DNS, MX records, SPF, DKIM, DMARC, provider setup and platform alignment. | How often emails are sent, who they are sent to and how recipients interact with them. |
| Common problem found | A platform is sending email without being authorised or signed correctly. | A domain or mailbox has low engagement, high complaint risk or sudden changes in volume. |
| Why it matters | Failed authentication can lead to rejection, quarantine or spam placement. | Poor sending patterns can damage reputation even when authentication records are valid. |
Email Deliverability Audit Checklist
Use this checklist before changing email providers, launching a new website, connecting a CRM or troubleshooting repeated spam issues.
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Identify every system that sends from the domain
Include staff mailboxes, website forms, marketing platforms, CRMs, accounting software, booking tools and automated notifications.
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Review DNS and authentication records
Check MX, SPF, DKIM and DMARC records for validity, duplication, missing includes, alignment issues and provider-specific requirements.
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Test real delivery paths
Send test messages from each platform, review headers where possible and confirm whether failures are technical, reputational or content-related.
When to Review
When Should a Business Request an Email Deliverability Audit?
Doing a Basic Check Internally vs Getting a Technical Audit
Internal Basic Check
- Suitable for checking obvious issues, such as whether SPF, DKIM and DMARC records exist.
- May be enough for a simple setup with one domain, one email provider and no third-party sending tools.
- Can help internal teams document which platforms are currently connected to the domain.
Technical Deliverability Audit
- More appropriate when several platforms send email, because authentication and alignment need to be checked across each source.
- Reduces the risk of changing DNS records without understanding their effect on mailboxes, website forms and third-party systems.
- Provides clearer prioritisation when problems involve provider configuration, domain reputation, spam filtering and business risk.
Connected Services
Services That Often Affect Email Deliverability
Email problems often involve more than the mailbox. Domain management, DNS, hosting and website forms can all affect whether business messages are delivered reliably.
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01
Domain Name Management
Protect your domain with managed DNS, renewal tracking and migration planning for Australian businesses that rely on secure website and email infrastructure.
View Service -
02
Email Hosting And Management
Reliable business email hosting and management with Microsoft 365 setup, DNS authentication, migration planning and support for businesses across Australia.
View Service -
03
Web Hosting
Managed web hosting for Australian businesses, built for speed, security and support with SSL, daily backups, server-level caching and proactive monitoring.
View Service
Email Deliverability Audit FAQs
These questions cover the practical concerns businesses often have before reviewing their email setup.
Can an email deliverability audit guarantee that emails reach the inbox?
Does Microsoft 365 still need SPF, DKIM and DMARC?
Can DNS changes break business email?
Need Help Reviewing Your Email Deliverability?
If your business emails are landing in spam, website form notifications are unreliable or your DNS records are unclear, we can review your email, domain and DNS setup and explain the next practical steps. Email delivery cannot be guaranteed, but a structured audit can remove avoidable technical problems and reduce provider finger-pointing.