Email Deliverability Guide for Australian E-Commerce Brands

Your email programme could have the best copy, the most beautiful design, and the most precisely segmented audience in your industry — and still fail completely if your emails don’t reach the inbox.

Email deliverability is the foundation that everything else rests on. For Australian e-commerce brands, there are specific factors that make deliverability management distinct: the AEST time zone creates different sending windows, the Australian Spam Act has specific requirements that affect list hygiene practices, and the relatively smaller Australian e-commerce market means brand reputation — with both recipients and ISPs — matters enormously.

This guide covers everything you need to know to maintain excellent inbox placement and build a sender reputation that ensures your emails land where they should.

What Is Email Deliverability?

Deliverability refers to the ability of your emails to reach your subscribers’ inboxes — rather than being filtered to spam, promotions tabs, or blocked entirely.

Deliverability is affected by:

Sender reputation: How email providers (Gmail, Outlook, Yahoo, iCloud Mail, Bigpond/Telstra) assess your trustworthiness as a sender
Email authentication: Whether your DNS records are properly configured to prove you own your domain
List quality: Whether your list contains valid, engaged subscribers who want your emails
Content quality: Whether your email content triggers spam filters
Sending behaviour: Volume, frequency, and consistency of your sending patterns

Poor deliverability doesn’t always mean your emails go to spam. Often it means they’re placed in the Gmail Promotions tab, filtered by Outlook’s junk folder, or silently not delivered at all. This is why deliverability problems can be invisible — your sending metrics look normal, but engagement is declining because fewer emails are actually reaching active inboxes.

Email Authentication: The Technical Foundation

Before anything else, your authentication records must be correctly configured. Without proper authentication, you’re building on sand.

SPF (Sender Policy Framework)

SPF tells receiving mail servers which IP addresses are authorised to send email on behalf of your domain. Without it, any mail server can send email claiming to be from your domain — which is a major red flag for spam filters.

Configure in your DNS: A TXT record listing your ESP’s sending servers as authorised senders. Your ESP (Klaviyo, ActiveCampaign, Campaign Monitor, HubSpot, or Mailchimp) will provide the specific record needed.

DKIM (DomainKeys Identified Mail)

DKIM adds a digital signature to every email you send. This signature allows receiving servers to verify the email genuinely came from your domain and hasn’t been tampered with in transit.

Configure in your DNS: A TXT record with a public key that pairs with the private key your ESP uses to sign outgoing messages. Your ESP provides the exact record.

DMARC (Domain-based Message Authentication, Reporting, and Conformance)

DMARC ties SPF and DKIM together and tells receiving servers what to do when authentication fails. It also sends you reports about who is sending email using your domain — essential for spotting phishing attacks.

Recommended DMARC policy for e-commerce brands:

Start with p=none (monitoring only, no action taken)
Move to p=quarantine after reviewing reports for 30–60 days
Aim for p=reject once you’re confident all legitimate sending sources are authenticated

Branded Sending Domain

If you’re on Klaviyo, one of the most impactful deliverability improvements you can make is setting up a branded sending domain. Instead of emails appearing to come from mail.klaviyo.com, they come from mail.yourbrand.com.au (or .com). This builds your own domain reputation rather than sharing Klaviyo’s shared reputation pool.

ActiveCampaign, Campaign Monitor, HubSpot, and Mailchimp all offer equivalent branded/custom sending domain options.

Australian Spam Act and Deliverability

The Spam Act 2003 and deliverability are directly connected. The Spam Act requires:

Consent — You must have consent from recipients before sending
Identification — Clear sender identification in every email
Unsubscribe — Functional unsubscribe mechanism in every email

Non-compliance creates deliverability problems because:

Sending to contacts without consent generates high spam complaint rates
High spam complaints damage your sender reputation with ISPs globally
ISPs share complaint data — high complaints with Gmail affect your Outlook reputation too

The consent-deliverability connection: The most common cause of deliverability problems in Australian e-commerce is sending to old or poorly consented lists. If you’ve been importing contacts from CRMs, scraping customers from old databases, or adding trade show contacts without explicit consent, those contacts will generate complaints that hurt your deliverability.

List Hygiene: The Ongoing Maintenance Programme

List hygiene is not a one-time task — it’s an ongoing programme that directly affects your deliverability.

Hard Bounce Management

Hard bounces occur when an email address is invalid — either it never existed or the mailbox has been permanently deactivated. Every ESP automatically suppresses hard bounced addresses, but you should monitor your bounce rate.

Target: Hard bounce rate under 0.5%

If your bounce rate exceeds 1%, investigate the source. High bounce rates typically indicate:

An imported list with old or invalid addresses
A sign-up form being exploited for fake registrations (use reCAPTCHA and double opt-in)
Poor data entry (Australian addresses with spelling errors, .con instead of .com)

Soft Bounce Management

Soft bounces are temporary delivery failures — a full mailbox, a temporary server issue, or a “this user doesn’t exist” response that may be temporary. ESPs retry soft bounces automatically and suppress contacts after a threshold of consecutive soft bounces.

Monitor soft bounce patterns. A spike in soft bounces can indicate a specific domain is having issues, or that you’re being rate-limited by a major ISP.

Unengaged Subscriber Management

This is the most impactful list hygiene practice for most Australian brands. Sending to large segments of unengaged subscribers destroys your sender reputation.

Define engagement windows:

Active: opened or clicked in the last 90 days
Warming: opened or clicked 91–180 days ago
At risk: 181–270 days, no engagement
Dormant: 271+ days, no engagement

Engagement-based sending strategy:

Active subscribers: Full campaign frequency (2–4 emails per week)
Warming: Reduced frequency (1–2 per week), consider a re-engagement flow
At risk: Dedicated win-back/sunset flow before suppression
Dormant: Suppress from standard campaigns; quarterly re-engagement email maximum

Many Australian brands are reluctant to suppress dormant contacts because “the list looks bigger.” This is a false economy — suppressing unengaged contacts improves your deliverability for everyone on your active list.

List Validation

Before sending to an imported or older list, run it through an email validation service (ZeroBounce, NeverBounce, Kickbox). These services check addresses for validity, syntax errors, disposable email domains, and spam traps — without actually sending.

Spam Traps: What They Are and Why They Matter

Spam traps are email addresses used by ISPs and anti-spam organisations to identify spammers. They come in two forms:

Recycled spam traps: Addresses that were once valid but have been deactivated and then converted to spam traps after a period of time. Sending to these indicates you’re not maintaining your list or removing bounced contacts.

Pristine spam traps: Addresses that were never valid and were never used to opt in to anything. Sending to these indicates you’re using purchased or scraped lists.

Hitting spam traps doesn’t immediately blacklist you, but repeated hits trigger reputation damage and filtering at major ISPs.

How to avoid spam traps:

Never purchase email lists
Remove hard bounces immediately (your ESP does this automatically)
Implement a sunset policy for unengaged contacts
Use double opt-in for new subscribers
Validate imported lists before sending

AEST Send Time Optimisation

Australian brands sending at times optimised for Northern Hemisphere audiences are making a significant mistake. A campaign scheduled for 10am EST New York time arrives at 2am AEST in Sydney — effectively invisible in an inbox.

Optimal AEST send windows for Australian audiences:

Tuesday–Thursday: 9:30am–11am AEST (highest engagement)
Monday: 10am–12pm AEST (slightly lower than mid-week)
Friday: 10am–11am AEST (engagement drops heading into weekend)
Avoid: Saturday and Sunday for promotional campaigns (lower engagement for most e-commerce categories)
Avoid: After 3pm AEST for campaigns (competing with end-of-day inbox sorting)

If you’re using Klaviyo, ActiveCampaign, Campaign Monitor, HubSpot, or Mailchimp, check your campaign scheduling is set to your subscribers’ local time or AEST — not UTC.

Time zone consideration: Australia spans multiple time zones — AEST (NSW, VIC, QLD, TAS, ACT), ACST (SA, NT), and AWST (WA). For most brands with majority eastern-seaboard audiences, optimise for AEST. If your audience is geographically distributed, consider time-zone-based send scheduling.

Content and Spam Filter Avoidance

Modern spam filters are sophisticated and go well beyond simple keyword detection. However, certain content patterns still cause problems:

Avoid:

Excessive use of capitals (CLICK HERE NOW, FREE SHIPPING TODAY ONLY)
Spam-associated phrases (“Make money fast”, “No obligation”, “Act now”)
Heavy image-to-text ratio (spam filters prefer text-balanced emails)
Broken links or links to domains with poor reputation
Link shorteners hiding the actual destination URL
Attachment files (use links to hosted content instead)

Best practices:

Maintain a healthy text-to-image ratio (aim for at least 40% text)
Always include a plain-text version of your email
Host all images on your own domain or reliable CDN
Use consistent “From” name and address — changes raise red flags
Keep your sending volume consistent week to week (dramatic spikes look suspicious)

Monitoring Your Deliverability

You need visibility into your deliverability performance. Key tools and metrics:

Google Postmaster Tools: Free tool from Google showing your domain reputation, IP reputation, spam rate, and authentication status as seen by Gmail. Essential for any Australian brand — Gmail (and its Google Workspace equivalent) has very high adoption in Australia.

Microsoft SNDS (Smart Network Data Services): Similar to Postmaster Tools but for Outlook/Hotmail. Important given Outlook’s significant share of Australian professional email.

Inbox placement testing: Tools like Litmus or Email on Acid show you whether your emails land in the inbox, promotions, or spam folder across major providers before you send.

Key metrics to track weekly:

Open rate trends (declining opens can signal deliverability issues)
Spam complaint rate (target: under 0.08%)
Hard bounce rate (target: under 0.5%)
Unsubscribe rate (high rates signal poor list quality or frequency issues)

Warming a New Domain or IP

If you’re setting up email on a new domain or switching ESPs, you must warm your sending infrastructure gradually.

New domain/IP warming schedule (example for a brand with 20,000 subscribers):

Week 1: Send to 500 most engaged subscribers only
Week 2: Expand to 2,000 most engaged
Week 3: Expand to 5,000
Week 4: Expand to 10,000
Week 5: Full list

During warming, send only to your most engaged segments. Positive engagement signals (opens, clicks) during the warming period build your domain reputation. Negative signals (complaints, spam folder placement) early in warming can permanently damage your reputation.

The Bigpond/Telstra Challenge

Bigpond (Telstra’s email service) is still used by a significant portion of older Australian email users. Bigpond applies relatively aggressive spam filtering and can be difficult to maintain good deliverability with.

To maintain Bigpond inbox placement:

Ensure SPF and DKIM are correctly configured
Maintain very low complaint rates
Don’t send to unengaged Bigpond addresses
Use plain-text alternatives
Avoid images-only emails

If you see specific deliverability problems with .bigpond.com or .bigpond.net.au addresses, check your authentication records and suppression hygiene for those domains specifically.

Deliverability Checklist for Australian Brands

SPF record correctly configured for your sending domain
DKIM signatures enabled and validated
DMARC policy in place (at minimum p=none with monitoring)
Branded sending domain configured
Hard bounces automatically suppressed
Unengaged subscribers sunset after 180–270 days
Win-back flow running for 91–180 day inactives
Google Postmaster Tools configured and monitored weekly
AEST time zone correctly set in campaign scheduling
Double opt-in enabled for new subscriber acquisition
Spam Act consent, identification, and unsubscribe requirements met

How Excelohunt Manages Deliverability

Excelohunt includes deliverability management as a core part of our done-for-you service for Australian e-commerce brands. We work across Klaviyo, ActiveCampaign, Campaign Monitor, HubSpot, and Mailchimp.

Our deliverability service includes:

Authentication audit and configuration (SPF, DKIM, DMARC)
Branded sending domain setup
List hygiene programme setup and management
Sunset flow build-out
Google Postmaster Tools monitoring
Spam Act compliance review

Want a Deliverability Audit?

Our free audit covers your authentication setup, list health, engagement metrics, and sending practices — and gives you a clear action plan to improve inbox placement.

Book your free email audit today and ensure your emails are landing where they should.