Email Deliverability for Ecommerce: The Australian Guide

Email deliverability is whether your emails land in the inbox, the spam folder or nowhere at all. For ecommerce brands it now comes down to three things: proper authentication (SPF, DKIM and DMARC), meeting the Gmail, Yahoo and Outlook sender rules, and only emailing people who want to hear from you. This guide covers all of it, plus the Australian Spam Act basics and how to warm a new sending domain in Klaviyo.

Key takeaways

• Set up SPF, DKIM and a DMARC record (at least p=none) on a branded sending domain. Gmail, Yahoo and Outlook all require it for bulk senders.
• Keep your spam complaint rate below 0.1% in Gmail and never let it reach 0.3%.
• Marketing emails need one-click unsubscribe, and Gmail and Yahoo expect unsubscribes honoured within two days.
• Australia's Spam Act 2003 requires consent, clear sender identification and a working unsubscribe actioned within 5 working days.
• Warm a new sending domain by emailing your most engaged subscribers first, then widen slowly.

What email deliverability means for ecommerce

Delivery and deliverability are not the same. A message is "delivered" when the receiving server accepts it. Deliverability is where it goes next: inbox, promotions tab or spam.

Inbox providers decide placement based on your sender reputation. That reputation is built from authentication, complaint rates, bounce rates and how people engage with your emails over time.

For a Shopify store this matters more than most. Your welcome series, abandoned checkout flow and campaigns all depend on the same reputation. If it drops, every email suffers at once, including the ones that make the most money. That's why deliverability is the first thing we check in any Klaviyo email marketing account.

SPF, DKIM, DMARC and BIMI explained

These four DNS records prove to inbox providers that your email really comes from you. You add them at your domain host (where your DNS is managed), and your email platform gives you the values.

SPF (Sender Policy Framework)

SPF lists the servers allowed to send email for your domain. When an inbox receives your email, it checks the sending server against that list. If the server isn't on it, SPF fails.

DKIM (DomainKeys Identified Mail)

DKIM adds a digital signature to every email. The receiving server checks the signature against a public key in your DNS. If it matches, the inbox knows the message wasn't altered and came from an authorised sender.

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

DMARC tells inboxes what to do when SPF or DKIM fails, and it checks that the domain in your "From" address lines up (aligns) with the domain that passed SPF or DKIM.

The policy has three levels: p=none (monitor only), p=quarantine (send failures to spam) and p=reject (block failures). Bulk sender rules require at least p=none. Moving to quarantine or reject gives stronger protection against spoofing once you're confident all your legitimate senders pass.

BIMI (Brand Indicators for Message Identification)

BIMI shows your logo next to your emails in supported inboxes. It's optional, but it only works once your authentication is in order.

According to Klaviyo's BIMI guide, you need:

• A DMARC policy of p=quarantine or p=reject applied to 100% of messages (pct=100). A p=none policy does not qualify.
• A square logo in SVG Tiny PS format, hosted over HTTPS.
• For Gmail, a Verified Mark Certificate (VMC, which needs a trademarked logo and shows a blue check) or a Common Mark Certificate (CMC, no trademark needed, no check).

Klaviyo lists Gmail, Yahoo and some versions of Apple Mail as supporting BIMI.

Google and Yahoo bulk sender requirements

Since February 2024, Gmail has required bulk senders to authenticate, keep complaints low and make unsubscribing easy. Google's sender guidelines FAQ says bulk sender status applies once you send close to 5,000 messages to personal Gmail accounts in 24 hours, and that status is permanent. It also says Gmail began ramping up enforcement in November 2025, with temporary and permanent rejections for non-compliant mail.

Yahoo's Sender Hub best practices set out the same core rules.

Even if your Australian store sends well under 5,000 emails a day, follow these rules anyway. A big sale or a list import can push you over the threshold in a single day, and the same practices improve inbox placement at any volume.

Microsoft Outlook's 2025 sender rules

Microsoft followed Google and Yahoo in 2025. Its announcement for high-volume senders applies to domains sending more than 5,000 emails a day to Outlook.com, Hotmail.com and Live.com addresses.

• SPF must pass for the sending domain.
• DKIM must pass.
• DMARC must be at least p=none and align with SPF or DKIM, preferably both.

Microsoft originally planned to send non-compliant mail to junk. It then updated the post to say messages that fail these checks would be rejected from 5 May 2025. Adding yourself to a recipient's safe sender list does not get around this.

Microsoft also recommends valid From and Reply-To addresses, a clear unsubscribe link, regular removal of invalid addresses and honest subject lines.

One-click unsubscribe and spam complaint thresholds

One-click unsubscribe

One-click unsubscribe uses a "List-Unsubscribe" header that lets inboxes like Gmail show an unsubscribe button next to your sender name. Google says the header must follow RFC 8058, and a mailto link or a link to a landing page on its own doesn't count. It applies to marketing and promotional email, not transactional email such as order confirmations.

Use your email platform's built-in unsubscribe handling rather than a custom page, keep a visible unsubscribe link in the footer as well, and test it on every template.

Spam complaint thresholds

Your spam rate is the share of delivered emails that recipients mark as spam. Gmail asks bulk senders to stay below 0.1% and never reach 0.3%. Yahoo's ceiling is 0.3%. Klaviyo's own warming guidance asks for complaint rates below 0.1% on flows.

To keep complaints down:

• Make the unsubscribe link easy to find. People who can't find it click "report spam" instead.
• Send what people signed up for, at the frequency you promised.
• Use a recognisable sender name and from address.
• Stop emailing people who haven't engaged in months.

Monitor your spam rate in Google Postmaster Tools, which reports Gmail data for your domain.

Email deliverability for ecommerce in Australia: the Spam Act 2003

Inbox rules decide where your email lands. Australian law decides whether you're allowed to send it at all. The Spam Act 2003 is enforced by the ACMA, and its guidance on avoiding spam sets three rules for commercial email and SMS.

1. Consent

You need consent before sending marketing messages. Express consent is when the person knowingly agrees to receive your marketing, such as ticking a box on a signup form. The ACMA calls this best practice.

Inferred consent can apply in some cases, such as an existing relationship where the person gave you their address directly. The ACMA notes it is not as reliable as express consent. Keep records of who consented, when and how.

Never buy or rent email lists. You can't show consent for those addresses, and they often contain dead and trap addresses that damage your reputation.

2. Identify

Every message must clearly identify your business and include accurate contact details.

3. Unsubscribe

The ACMA's unsubscribe fact sheet says your unsubscribe option must:

• have clear instructions
• be actioned within 5 working days
• work for at least 30 days after you send the message
• not charge a fee
• not require the person to create or log in to an account, or give extra personal information

Note the gap: the law allows 5 working days, but Gmail and Yahoo expect unsubscribes handled within two days. Meet the stricter standard. This is general information, not legal advice.

Unsure whether your signup forms and checkout collect valid consent? Ask us to review them.

List hygiene that protects your sender reputation

Clean lists get better inbox placement. Build these habits into your email marketing routine.

• Segment by engagement. Send most campaigns to people who have opened, clicked or bought recently. Mail the less engaged less often.
• Run a sunset flow. Give long-term non-openers a final chance, then suppress them.
• Remove hard bounces. Invalid addresses hurt your reputation every time you send to them.
• Use double opt-in for risky sources. Confirming the address cuts typos, fake signups and spam traps.
• Don't email old lists cold. If an address hasn't heard from you in a year or more, treat it as unengaged.
• Watch open rates with care. Apple Mail Privacy Protection inflates opens, so look at clicks and orders too.

How to set up and warm a dedicated sending domain in Klaviyo

Without a branded sending domain, Klaviyo emails show "via klaviyomail.com" next to your sender name. A branded (dedicated) sending domain puts your own domain on the email and gives you control of your reputation.

Set up the domain

1. Choose an unused subdomain of your main domain, for example send.yourstore.com.au. Klaviyo's branded sending domain guide says "send" is the most common choice.
2. Add the DNS records Klaviyo generates at your domain host. Dynamic routing (NS records) is Klaviyo's recommended option; static routing uses CNAME records. A TXT record verifies ownership.
3. Add a DMARC record if you don't have one. Klaviyo can generate a basic p=none record during setup.
4. Verify and activate the domain in Klaviyo.

Klaviyo says new accounts, or domains registered in the last 30 days, should warm their marketing sending. Existing senders whose domain is older than 30 days and already used for email usually don't need to re-warm.

Warm the domain

Warming builds trust by starting with your most engaged subscribers and widening the audience as engagement holds. Klaviyo's domain warming guide lays out this ramp:

• Start with people who clicked in the last 30 days or subscribed in the last 15 days.
• Keep your first campaign under 10,000 recipients and aim for open rates above 30%.
• Only move to the next stage while open rates stay at or above 20%. If they fall below that, pause the ramp.
• Switch flows on in stages: welcome after about two weeks of campaigns, abandoned cart after about 30 days, browse abandonment after 30 to 60 days. Hold winback and sunset until warming is complete.
• Keep sending. Guided warming can time out after 45 days without a campaign to at least 1,000 recipients.

Email deliverability checklist

1. Branded sending domain set up and verified in Klaviyo.
2. SPF and DKIM passing, DMARC published and aligned.
3. One-click unsubscribe working, plus a visible footer link.
4. Business name and contact details in every email.
5. Consent recorded for every subscriber.
6. Spam rate checked in Google Postmaster Tools.
7. Engagement-based segments and a sunset flow running.
8. New domains warmed before full-list sends.

Want someone to check this for you? Our Klaviyo email marketing team audits authentication, list health and sending practices as part of every setup.

Related reading: Klaviyo Flows for Shopify: The 9 Essential Automations and Klaviyo List Bombing: What It Is and How to Stop It.

FAQs

What is a good spam complaint rate for ecommerce email?

Gmail asks bulk senders to keep their user-reported spam rate below 0.1% and never reach 0.3%. Yahoo's limit is 0.3%. Aim for the lowest number you can, because every complaint counts against your sender reputation.

Do the Gmail and Yahoo rules apply to small Australian stores?

The strictest rules apply to bulk senders, which Gmail defines as close to 5,000 messages to personal Gmail accounts in a day. Smaller stores should still follow them, because one big send can push you over, and the same practices improve inbox placement at any size.

Do I need BIMI to get into the inbox?

No. BIMI only displays your logo in supported inboxes. It needs a DMARC policy of quarantine or reject and, for Gmail, a VMC or CMC certificate. Get SPF, DKIM and DMARC right first.

How fast do I have to process unsubscribes in Australia?

The Spam Act 2003 requires unsubscribe requests to be actioned within 5 working days, according to the ACMA. Gmail and Yahoo expect two days for bulk senders, so aim to process unsubscribes immediately.

How long does it take to warm a sending domain in Klaviyo?

There's no fixed length. Klaviyo's ramp moves in stages of about two weeks, reaching the 90-day engaged segment after roughly four weeks if open rates stay at or above 20%, then widening further from there.

Can I email customers who bought from my store?

Possibly, under inferred consent, if they gave you their address as part of an existing relationship. The ACMA says express consent is more reliable, so add a clear marketing opt-in at checkout and keep records.

Fix your email deliverability

Strong email deliverability means every flow and campaign you send has a real chance of being seen. We set up authentication, warm sending domains and keep lists clean for Australian ecommerce brands on Klaviyo. Get a free quote and we'll check your setup.