Why are Bigpond emails bouncing with a content-based spam reason?

Key findings

• Content-based rejection: The specific bounce message "Message content rejected due to suspected spam. IB703" confirms that the issue stems from the email's actual content rather than IP reputation or authentication failures.
• ISP sensitivity: Bigpond's spam filtering thresholds are reportedly very tight, meaning even minor content deviations or subtle increases in negative metrics can lead to blocks.
• User complaints impact: User complaints directly influence content-based filtering, suggesting that recipients are marking your emails as spam, which then informs the ISP's filters.
• Emoji considerations: While some ISPs (like Gmail with specific reserved emojis) can block based on subject line emojis, it's generally less likely to be the primary cause for Bigpond compared to overall content quality.

Key considerations

• Content audit: Thoroughly review the content of the problematic mailings for common spam triggers, such as excessive capitalization, poor grammar, unusual formatting, or overly promotional language. For more information on common deliverability issues, read our guide on email deliverability issues.
• Subject line optimization: Experiment with subject lines, potentially removing emojis or special characters if they are present, to see if it improves deliverability to Bigpond. While not always the primary cause, it's an easy variable to test.
• Monitor engagement: A decrease in positive engagement (opens, clicks) and an increase in negative engagement (spam complaints) can signal content problems. Address the root cause of subscriber dissatisfaction.
• Contact postmaster: Consider reaching out to Telstra's postmaster (Bigpond) for specific feedback on why your emails are being blocked. Their postmaster services are known to be helpful in diagnosing issues or resolving false positives.
• Broader deliverability assessment: If a small subset of Bigpond emails is bouncing, it could be an early warning sign of broader deliverability issues impacting your overall sender reputation. Investigate the health of your entire email program. For more on Bigpond bounces, refer to our specific article on why emails to Bigpond bounce. Additionally, you can find a comprehensive guide on how to solve email delivery issues externally.

Key opinions

• Content is paramount: Marketers frequently identify content as the primary suspect for rejections, particularly when the bounce message explicitly states a content-based reason.
• Emoji caution: Anecdotal evidence among marketers suggests that emojis in subject lines and links to videos can correlate with lower engagement and reduced inbox placement, even if not scientifically proven.
• User complaints are a factor: Some marketers believe that recipient spam complaints contribute directly to content-based blocks, indicating the importance of subscriber feedback.
• List hygiene matters: An outdated or unengaged email list is commonly cited as a major contributor to bounces, which can indirectly lead to content issues being flagged more often as overall sender reputation declines.

Key considerations

• Test content variations: Marketers should actively test different email content and subject line variations to determine what resonates best with their audience and avoids spam filters. This is part of how to increase email click through rate.
• Review promotional emails: Promotional emails, especially to B2C webmail addresses like Bigpond, are often subject to stricter content scrutiny. Ensure they adhere to best practices for commercial sending.
• Consider emoji removal: Although not a universal cause, if emojis are present in subject lines or content, removing them for A/B testing can help isolate the content issue. This can also help when emails are going to spam. For more on general bouncing reasons, check Inc's article on 4 reasons your emails are bouncing.

Key opinions

• Content is the primary driver: Experts largely agree that a "content rejected" bounce reason almost certainly points to an issue with the email's body, subject line, or links.
• Warning signs: Content blocks, even for a small subset of recipients, should be treated as significant warning signs that warrant a thorough investigation of the mailings.
• ISP-specific behavior: While some ISPs might have specific rules (e.g., Gmail's reserved emojis), experts advise focusing on what's typical for the given ISP until data strongly suggests otherwise. Bigpond is generally known for content sensitivity, not emoji blocking.
• Holistic filtering: Modern spam filters are sophisticated, evaluating content in conjunction with sender reputation, formatting, and engagement signals.

Key considerations

• Deep dive into mailings: Experts recommend a comprehensive review of the exact email content, including subject lines, body text, image-to-text ratio, and links, that triggered the Bigpond block. This can greatly assist in boosting email deliverability rates.
• Leverage ISP postmaster support: Engaging with the Bigpond postmaster can provide specific insights into their filtering mechanisms and help resolve content-related issues.
• Understand domain reputation: While a content block, the overall health of your domain reputation can amplify or mitigate content-related issues. Regularly monitor and work to improve your email domain reputation. Additionally, an external resource on spam filtering evolution is available.

Key findings

• RBL integration: Most mail servers are configured to check incoming mail against Real-time Blackhole Lists (RBLs), which can list IPs or domains associated with spamming. While this specific bounce is content-based, an IP or domain on a blocklist (or blacklist) can exacerbate content issues.
• Content triggers: Documentation often lists specific content characteristics, such as excessive capitalization, poor grammar, or overuse of punctuation, as common triggers for spam filters. For a deeper understanding of blocklists, consult our in-depth guide to email blocklists.
• List quality impact: Outdated or unengaged email lists are a significant cause of bounces, which negatively impacts sender reputation and makes content more susceptible to being flagged.

Key considerations

• Adhere to content best practices: Follow widely accepted guidelines for email content to minimize the chances of triggering spam filters. Avoid characteristics that documentation identifies as problematic.
• Maintain list hygiene: Regularly clean your email lists to remove inactive or invalid addresses, reducing bounce rates and improving overall sender reputation. This is a critical step for successful email deliverability. Consider running a thorough email deliverability test with a proven checklist. More information on email bounce reasons can be found from johnA's blog regarding Telstra Bigpond.
• Understand bounce reasons: Familiarize yourself with common bounce codes and their meanings to quickly diagnose and address deliverability problems as they arise. This involves knowing the difference between a blacklist and a blocklist.