# How to Avoid Spam Filters With Compliant Email Content
In the digital age, your email list is one of your business's most valuable assets. However, if your messages are consistently caught in spam filters, you aren't just losing potential sales—you're damaging your brand’s reputation and risking legal penalties under Australian law.
This guide will walk you through the essential steps to ensure your email content is technically sound, legally compliant, and designed to land directly in your customers' inboxes.
Prerequisites: What You’ll Need
Before you start drafting, ensure you have the following:- An account with an Email Service Provider (ESP) like Mailchimp, HubSpot, or ActiveCampaign.
- A verified domain email address (e.g., hello@yourbusiness.com.au rather than @gmail.com).
- Your Australian Business Number (ABN) and physical business address for footer compliance.
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Step 1: Understand the Australian Spam Act 2003
Before writing a single word, you must understand the legal landscape. The Australian Communications and Media Authority (ACMA) enforces the Spam Act 2003. To be compliant, every commercial email must meet three criteria: Consent, Identity, and Unsubscribe.- Consent: You must have express or inferred consent from the recipient.
- Identity: Your email must clearly identify you or your business.
- Unsubscribe: You must provide a functional way for people to opt-out.
Step 2: Clean Your Subject Lines
Spam filters scan subject lines for "trigger words" and aggressive formatting. Avoid using all caps (e.g., "OPEN NOW") or excessive punctuation (e.g., "SALE!!!"). What you should see: A subject line that is descriptive and honest. If you are offering a 20% discount, say "Your 20% discount inside" rather than "YOU WON A PRIZE!"Step 3: Maintain a Healthy Image-to-Text Ratio
Spammers often hide text inside images to bypass filters that scan for keywords. Consequently, filters are suspicious of emails that are just one large image. Aim for a ratio of approximately 60% text to 40% images.Pro Tip: Always include "Alt Text" for your images. This is the text that appears if the image fails to load, and it helps filters understand that your content is legitimate.
Step 4: Include a Clear Physical Address
To comply with international and Australian anti-spam laws, you must include a physical postal address in your email footer. This proves you are a legitimate entity. Manual Check: Look at the bottom of your email draft. You should see your business name, ABN (highly recommended for Australian trust), and a physical or PO Box address.Step 5: Implement a One-Click Unsubscribe
Australian law requires that an unsubscribe request be easy to find and functional. It must be processed within five business days. The best practice is a "one-click" unsubscribe link in the footer. Common Mistake: Hiding the unsubscribe link by making the font colour match the background. This is a fast track to being blacklisted by ISPs (Internet Service Providers).Step 6: Avoid "Spammy" Keywords in Body Copy
Modern filters are sophisticated, but they still flag certain words associated with phishing and scams. Be cautious with words like "Guarantee," "No cost," "Urgent," "Winner," and "Work from home."In a business context, focus on value-driven language. Instead of "Buy now for cheap," try "Explore our affordable range."
Step 7: Personalise the "To" Field
When an email is addressed to a specific name (e.g., "Dear Sarah") rather than a generic "Dear Customer" or just an email address, it passes through filters more easily. Most ESPs allow you to use "Merge Tags" to pull the recipient's first name from your database.Step 8: Optimise Your Preheader Text
The preheader is the short summary text that follows the subject line when viewed in an inbox. Screenshot Description: In your ESP editor, you will usually see a field labelled "Preview Text" or "Preheader" right below the Subject Line field. Ensure this text complements the subject line without being repetitive.Step 9: Check Your Links
Broken links or links that use URL shorteners (like bit.ly) are often flagged as suspicious. Spammers use shorteners to hide the final destination of a link. Action: Use full, descriptive links or buttons linked directly to your verified website domain (e.g., yourbusiness.com.au/offer).Step 10: Authenticate Your Domain (SPF, DKIM, and DMARC)
While this is slightly technical, it is the most important step for deliverability. These are digital "passports" that prove to the receiving server that the email actually came from you.- SPF (Sender Policy Framework): Lists which IP addresses are allowed to send email on your behalf.
- DKIM (DomainKeys Identified Mail): Adds a digital signature to your emails.
- DMARC: Tells servers what to do if the SPF or DKIM fails.
Step 11: Run a Spam Test Before Sending
Before hitting 'Send' to your entire list, use a tool like Mail-Tester.com. These tools provide a score based on your content, links, and technical setup. What you should see: A report highlighting if your IP is blacklisted, if your images are missing alt-tags, or if your authentication records are missing.---
Common Mistakes to Avoid
- Buying Email Lists: This is the fastest way to get marked as spam. In Australia, sending to a bought list usually violates the Spam Act because you lack consent.
- Using Red Font: For some reason, spam filters dislike large amounts of red text. Stick to standard professional colours.
- Large Attachments: Never send attachments to a large marketing list. Instead, host the file on your website or Google Drive and provide a link.
Troubleshooting Common Issues
Problem: My emails are still going to the 'Promotions' tab in Gmail.- Solution: This isn't necessarily a spam filter, but a categorisation. To avoid this, reduce the number of links and images, and try to write in a more personal, one-to-one tone.
- Solution: Check your site on MXToolbox. If you are blacklisted, you must contact the blacklist provider or work with your ESP to prove you have cleaned your list and are following best practices.
- Solution: This usually means your list is old. Use a list cleaning service to remove inactive or non-existent email addresses before your next send.
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Next Steps
Now that your content is compliant, it's time to focus on engagement. Read our guide on "How to Increase Email Open Rates for Brisbane Businesses" or learn how to "Set Up Automated Welcome Sequences."If you're worried about your technical setup or need help staying on the right side of the ACMA, we can help. Contact the team at Local Marketing Group for an email deliverability audit.