Email Deliverability Checklist for New Zealand Businesses

If your invoices, quotes or marketing emails are landing in the spam folder, you're not just losing sales — you're losing trust. For New Zealand businesses competing with larger brands and international senders, strong email deliverability is essential. Since Google and Yahoo tightened their bulk sender rules in 2024, getting the fundamentals right is no longer optional.

This checklist walks you through every step, from DNS authentication to sender reputation, so your emails reliably reach customers in Auckland, Wellington, Christchurch and beyond.

What Is Email Deliverability?

Email deliverability is the ability of your messages to reach the recipient's inbox — not the spam folder, not bounced, not silently dropped. It depends on three things:

  • Authentication: Can mailbox providers verify you sent the email?
  • Reputation: Do your sending domain and IP have a good track record?
  • Content & engagement: Do recipients open, reply and avoid marking you as spam?

Let's tackle each area.

1. Authenticate Your Domain (SPF, DKIM, DMARC)

Authentication is the foundation. Without it, Gmail, Outlook and Xtra will treat your mail as suspicious.

Step 1: Set Up SPF

SPF (Sender Policy Framework) tells receiving servers which IPs or services are allowed to send mail for your domain. Publish a single TXT record at your root domain.

Example for a Kiwi business using Microsoft 365 and Mailchimp:

yourbusiness.co.nz.  IN  TXT  "v=spf1 include:spf.protection.outlook.com include:servers.mcsv.net -all"

Key rules:
- Only one SPF record per domain.
- Keep it under 10 DNS lookups.
- End with -all (strict) once you're confident, or ~all (soft fail) while testing.

Step 2: Enable DKIM

DKIM (DomainKeys Identified Mail) cryptographically signs your emails so receivers can verify they haven't been tampered with. Most providers generate DKIM keys for you — you just publish the CNAME or TXT records they supply.

Example CNAME record from Microsoft 365:

selector1._domainkey.yourbusiness.co.nz.  IN  CNAME  selector1-yourbusiness-co-nz._domainkey.yourtenant.onmicrosoft.com.

Enable DKIM for every service that sends on your behalf: your email host, CRM, helpdesk, invoicing tool (Xero, for example, signs via its own domain by default, but custom sending domains need DKIM configured).

Step 3: Publish a DMARC Record

DMARC ties SPF and DKIM together and tells receivers what to do when a message fails. Start in monitoring mode:

_dmarc.yourbusiness.co.nz.  IN  TXT  "v=DMARC1; p=none; rua=mailto:dmarc@yourbusiness.co.nz; fo=1; adkim=r; aspf=r"

After 2–4 weeks of reviewing reports, move to p=quarantine, then p=reject. This protects your brand from spoofing — critical for NZ businesses targeted by invoice fraud.

2. Configure Reverse DNS and a Branded Sending Domain

  • PTR / reverse DNS: If you send from your own server, ensure the IP resolves back to your hostname. Your ISP (Spark, 2degrees Business, Voyager) can set this.
  • Use a subdomain for bulk mail: Send newsletters from news.yourbusiness.co.nz and keep transactional mail on your main domain. This protects your primary reputation.
  • Avoid free-domain senders: Don't send business mail from @gmail.com or @xtra.co.nz. Use your own .co.nz or .nz domain.

3. Warm Up New Domains and IPs

A brand-new domain has no reputation. If you suddenly blast 5,000 emails, filters will flag you.

  1. Start with 50 emails a day to your most engaged contacts.
  2. Double the volume every 2–3 days.
  3. Monitor bounces and spam complaints at each stage.
  4. Reach full volume over 3–4 weeks.

4. Clean and Maintain Your List

Deliverability collapses fast with a dirty list. Follow these rules:

  • Use confirmed opt-in wherever possible — it's also aligned with the NZ Unsolicited Electronic Messages Act 2007.
  • Remove hard bounces immediately.
  • Suppress unengaged contacts after 6 months of no opens or clicks.
  • Never buy lists. You'll burn your domain and breach NZ anti-spam law, which carries fines up to $500,000 for organisations.
  • Include a clear unsubscribe link in every commercial email — required by law and expected by mailbox providers.

5. Write Content That Passes Filters

Spam filters evaluate more than authentication. Watch for:

  • Balanced text-to-image ratio (avoid image-only emails).
  • No misleading subject lines or excessive CAPS and exclamation marks.
  • Working, HTTPS links — avoid URL shorteners like bit.ly for business mail.
  • A physical NZ address in the footer (builds trust and meets best practice).
  • Plain-text version alongside HTML.

6. Monitor Sender Reputation

Reputation is measured by mailbox providers, but you can track leading indicators:

  • Google Postmaster Tools — essential if you send to Gmail users.
  • Microsoft SNDS — for Outlook, Hotmail and Xtra (Xtra uses Outlook infrastructure).
  • Blocklist checks — Spamhaus, Barracuda and SURBL.
  • DMARC aggregate reports — parse the XML reports at your rua address.

Aim for a spam complaint rate under 0.1% and a bounce rate under 2%.

7. Align With the 2024 Bulk Sender Requirements

If you send more than 5,000 emails a day to Gmail or Yahoo addresses, you must:

  1. Authenticate with SPF and DKIM.
  2. Publish a DMARC policy (at least p=none).
  3. Ensure your From domain aligns with SPF or DKIM.
  4. Include a one-click unsubscribe header (List-Unsubscribe).
  5. Keep spam complaints below 0.3%.

Even if you send less, meeting these standards is now the baseline for good deliverability.

8. Quick Pre-Send Checklist

Before your next campaign:

  • [ ] SPF record published with -all or ~all
  • [ ] DKIM enabled on every sending service
  • [ ] DMARC published (start at p=none)
  • [ ] List cleaned of bounces and unengaged contacts
  • [ ] Unsubscribe link visible and working
  • [ ] From name and address recognisable
  • [ ] Test send reviewed on mobile and desktop
  • [ ] Inbox placement tested across Gmail, Outlook and Xtra

Check Your Domain in Seconds With xteam MailCheck

Not sure if your SPF, DKIM and DMARC are configured correctly? Try xteam's free MailCheck tool — built specifically for New Zealand businesses. In under 30 seconds you'll get a clear report on your authentication records, inbox placement risks and exactly what to fix.

Strong deliverability isn't a one-off task — it's ongoing hygiene. With the right foundations and regular monitoring, your emails will land where they belong: in front of your customers.