Email Deliverability Guide for Australian Businesses

Deliverability is the foundation of email marketing. You can write the perfect subject line and design a beautiful template, but if Gmail, Outlook, or Yahoo route your emails to spam, none of it matters. For Australian businesses sending to local and international subscribers, getting the technical and behavioural basics right is non-negotiable.

Authenticate your sending domain

SPF, DKIM, and DMARC records tell receiving servers that your emails are legitimate. Most Australian businesses send through platforms like Mailchimp, Klaviyo, or Brevo — each provides DNS records to add via your domain host. Without authentication, inbox placement drops sharply.

Use a dedicated sending subdomain

Send marketing email from something like mail.yourbusiness.com.au rather than your root domain. This isolates marketing reputation from transactional email like order confirmations and password resets, protecting both channels.

Maintain list hygiene

• Use double opt-in or confirmed signup for new subscribers
• Remove hard bounces immediately after each send
• Sunset or re-engage contacts inactive for 6–12 months
• Never purchase or scrape email lists

Watch your sender reputation metrics

Monitor bounce rate, spam complaint rate, and unsubscribe rate after every campaign. Google Postmaster Tools and your email platform’s deliverability dashboard show whether reputation is healthy. A complaint rate above 0.1% is a warning sign worth investigating.

Balance images, links, and copy

Emails that are image-only, stuffed with links, or full of spam trigger words get filtered more often. Include a healthy text-to-image ratio, one clear primary link, and an easy unsubscribe option. Australian spam laws require a functional unsubscribe — it also protects your reputation.

Warm up new domains and IPs gradually

If you are switching platforms or sending from a new domain, ramp up volume slowly over two to four weeks. Start with your most engaged subscribers and increase send size incrementally. Sudden high-volume sends from a cold domain trigger spam filters.