Emails Going to Spam? Fix SPF, DKIM and DMARC in Australia — Email Deliverability Guide

Stop losing quotes, invoices and enquiries to the spam folder—start landing in inboxes. This guide explains SPF, DKIM and DMARC in plain English. It’s made for Brisbane SMEs using Microsoft 365, Google Workspace, or local hosts like VentraIP and Crazy Domains. It targets better email deliverability fast.

Sick of emails landing in spam? Learn SPF, DKIM and DMARC basics, fix common errors, and improve deliverability. Step-by-step checks and local help for Brisbane SMEs.

Key takeaways

• SPF says who can send for your domain. DKIM signs your mail. DMARC ties them together and sets your policy.
• Start DMARC at p=none, read the reports, then move to quarantine or reject with confidence.
• Keep SPF under the 10-lookup limit. Use include for real senders only.
• Bad content, broken links, or sending spikes can hurt reputation and raise bounce rate.
• Brisbane quirks: NBN dropouts, storm outages and old routers can cause timeouts and false bounces.

What email deliverability is and core concept

Definition

Email deliverability is the chance your email reaches the inbox, not spam or a bounce. It’s driven by email authentication (SPF, DKIM, DMARC), server reputation, content quality, links, sending history, and user actions. Think of it like ID checks for your domain plus a trust score for your mail.

Why it matters

Missed inboxes cost real money in Brisbane. Quotes to tradies in Capalaba, invoices to cafés in Paddington, bookings in South Bank—if your mail sits in junk, the day goes sideways. Clean records reduce blacklists, reduce bounce rate, and keep Outlook and Gmail happy. That means faster replies and more sales.

How it works and step-by-step

Process

Follow this simple flow to lift inbox placement:

• Test your domain: Use MXToolbox for SPF, DKIM, DMARC lookups. Check Google Postmaster and Microsoft reports if available.
• Map senders: List all systems that send mail: Microsoft 365/Outlook, Google Workspace, website forms, Mailchimp, Xero/MYOB, CRM, VoIP phones, scanners.
• Fix SPF: Keep one SPF record. Add “include” for each real sender. Avoid more than 10 DNS lookups.
• Enable DKIM: Turn on DKIM in Microsoft 365 or Google. For other platforms, publish the DKIM public key in DNS. Rotate keys every 6–12 months.
• Set DMARC: Start with p=none; rua= for reports. Watch alignment. Then move to quarantine, then reject.
• Content and links: Use a clear From name, real reply-to, short subject, and clean links. Avoid URL shorteners.
• Check blacklists: Look up your sending IP and domain. If listed, fix the cause and request removal.
• Monitor: Track open rates, bounce rate, and complaint rates. Review DMARC reports weekly for a month, then monthly.

Featured answer

To stop emails going to spam, publish a single SPF record, enable DKIM signing, and set a DMARC policy starting at p=none. Verify each tool sending mail for your domain, keep SPF under the 10-lookup limit, and monitor DMARC reports. Tweak content and links, then move to quarantine or reject.

Common problems in Brisbane

Weather and infrastructure

• Storm season outages: Summer storms and humidity in Brisbane, Logan and Redlands cause NBN dropouts. Mail queues can back up, time out, and spike bounces.
• Older buildings: Older CBD and Woolloongabba blocks with old routers or double-NAT can cause reverse DNS or SMTP handshake issues on local mail servers.
• NBN quirks: CG-NAT on some plans (Aussie Broadband, iiNet) complicates on-prem mail relays. Use cloud relays or authenticated SMTP instead.
• Hot server rooms: Heat in small offices from Springwood to North Lakes can throttle NAS or on-prem SMTP, causing delays and retries.

Troubleshooting and quick checks

Short answer

Run an SPF, DKIM and DMARC check. Remove extra SPF records, enable DKIM in your email platform, and add a DMARC TXT with p=none and reporting. Test to Outlook and Gmail. If deliverability improves, move to quarantine, then reject. Keep SPF within the lookup limit and fix broken links.

Quick checks

Do these safe checks any time:

• One SPF record only. It should start with v=spf1 and end with ~all or -all.
• Count SPF lookups. Stay at 10 or less. Remove dead includes.
• Turn on DKIM in Microsoft 365 or Google; send a test to Gmail and view original to see “DKIM=PASS”.
• Add DMARC: v=DMARC1; p=none; rua=mailto:dmarc@yourdomain; adkim=s; aspf=s.
• Content: Use your domain in links. Avoid link shorteners and large image-only emails.
• Reply path: Set a working reply-to on your domain.
• Rate: Send in steady batches. Avoid big spikes that look like spam.
• Blocklists: Check domain and sending IP. Fix the cause before delisting.
• Inbox tests: Send to Outlook.com, Gmail and a Telstra BigPond address to compare results.

Safety notes and when to call a pro

Red flags

If you see multiple SPF records, a sudden rise in bounce rate, DMARC showing unknown sources sending as your domain, or you find your domain on a blacklist, stop big sends. Don’t switch to -all or reject without checking alignment. Call a pro if invoices or password resets are going missing.

Time matters if you run rosters, bookings or job quotes. If you rely on Outlook shared mailboxes, scanners, or CRMs like HubSpot or Zoho, get help setting SPF includes and DKIM keys right the first time.

Local insights and examples

Brisbane/SEQ examples

We often see trades in Brendale using cPanel mail plus a website form on a different host. The SPF only lists the cPanel server, so website form emails fail SPF and land in junk. Fix: add the web host include or relay the form through Microsoft 365 with DKIM.

Retail in Chermside using Mailchimp plus Microsoft 365 sometimes hits the SPF lookup limit. They include too many CRMs and old hosts. Fix: remove old includes, use MX-based mechanisms only when needed, and prefer platform-recommended include records.

Accountants in Fortitude Valley sending PDF invoices from Xero see Gmail spam flags from mismatched links. Fix: align the From domain, set DKIM in Xero/Microsoft 365, and use branded links. Result: higher inbox placement and fewer client “didn’t get it” calls.

Hospitality in South Bank sees spikes on Friday arvo promos. Too many recipients at once can trigger rate limits on some providers. Fix: schedule batches and warm the domain after a quiet period like Christmas break.

FAQs

Q1: How do I fix SPF without going over the 10-lookup limit?

List every sender you truly use. Remove old includes from past hosts. Use the provider’s single include record (for example Microsoft or Google) rather than listing IPs by hand. Avoid ptr and excessive a/mx mechanisms. If needed, use a dedicated relay to cut lookups.

Q2: What DMARC policy should I start with?

Start with p=none so you can read reports safely. Set rua to a mailbox you read. Check that real mail aligns (SPF or DKIM pass with alignment). When the reports look clean, move to p=quarantine at 20–50% (pct tag), then to p=reject at 100%.

Q3: How long until results show?

DNS updates often take 5–60 minutes, sometimes up to a few hours depending on TTL. Inbox results can improve the same day once SPF/DKIM pass. DMARC reports usually arrive within 24 hours. Reputation recovery after a blacklist can take days to a few weeks.

Sources and further reading

Core standards: SPF (sender policy in DNS), DKIM (cryptographic signing of headers), DMARC (policy and reporting with SPF/DKIM alignment). Provider tools: Google Postmaster and Microsoft reports show spam rate, domain reputation and authentication pass rates. Common patterns: one SPF record, DKIM on, DMARC with reporting, then staged enforcement.

Wrap-up and next steps

Fixing SPF, DKIM and DMARC is the fastest path to better inbox results in Brisbane. Map your senders, publish clean records, start DMARC at none, and tune content and links. If time is tight or mail is business‑critical, we can help same day. Service:
Email Setup & Troubleshooting