How do I avoid my mailing being categorized as spam?

Why is Your Mailing Classified as Spam?

Spam filters analyze mailings based on numerous criteria, including sender address and subject line. If a specific number of these criteria are met, the mailing is classified as spam. The exact algorithms are not disclosed by providers to prevent spammers from bypassing them. However, you can test the results.

Additional Requirements for High Volume Sending:

To ensure that more than 5,000 emails per day can be delivered to providers like Gmail or Yahoo, it is crucial that your sending domain's spam rate and IP reputation remain below 0.3%.

For more information about your spam rate, contact our support team.

Modern Technologies and AI in Spam Detection:

Even with the perfect implementation of technical measures like DKIM, SPF, and DMARC, modern AI systems can identify spam based on behavioral patterns and content indicators. These systems operate independently of how well the sender's technical setup is configured.

More information on DKIM, SPF, and DMARC can be found in our article "What are MX, SPF, DKIM and DMARC records?"

How to Test the Spam Classification of Your Mailing?

Open your mailing, go to the "Test" tab, and click on Spam Test. Your mailing will pass through real spam filters in the mailboxes of various providers. After the test, you will receive results per provider. External tools like mail-tester.com or Postmark Spamcheck can provide additional insights.

What to Do About a Negative Classification in the Spam Check?

Review potential causes and address them step by step. Then repeat the deliverability test until the classification is "green" with all providers.

Additional Considerations:

• Keep the spam rate under control: Ensure that your domain's spam and complaint rate remain below 0.3%. This positively impacts your reputation and increases deliverability for large mailings.

For more information about your spam rate, contact our support team.

• Sender Domain Reputation: Maintain your sender domain and avoid negative feedback from spam filters.

Sender:

• Use a consistent sender address. Frequent changes weaken reputation.

• Ensure that the sending domain used for internal links remains constant.

Subject Line:

• Avoid excessive use of special characters (!!!, $$$).

• No exaggerated slogans like "200% Profit!"

• The subject line should not exceed 25 characters.

Content:

• No hidden or barely readable text.

• Text should clearly dominate; limit image usage.

• Links should only point to trustworthy and existing pages.

• Avoid "spam words" like win, buy, free.

Mailing Structure:

• Use "Multi-Part" sending with plaintext and HTML.

• Avoid attachments; instead, link to files.

Address Quality:

• Use only addresses with valid opt-ins. Poor data quality increases bounces and spam marks.

Tip: Maintaining your address data and adhering to these criteria are crucial for building a positive sender reputation in the long term.

What Can I Do If My Mailing Lands in the Spam Folder Despite Positive Tests?

Spam filters are individually adjusted by servers and users. In addition to the content, the following actions can help:

1. Server-Side Actions:

• Configure SPF, DKIM, and DMARC correctly.

• Add your sending IP addresses to the recipient company's whitelist.

You can find the sending IP addresses here

2. Recipient-Side Actions:

• Ask recipients to add your sender address to their address book.

• Monitor spam complaints and take action in case of recurring issues.

3. Bypassing AI Detection:

• Monitor spam flags for your mailings. Spam filters and AI systems use past data for future evaluations.

• Work continuously to keep your spam and complaint rates low.

4. Building a Sustainable Reputation:

• Ensure your domain has a positive history with major providers like Gmail.

• Consistently focus on high-quality content and clean data.

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