Summary
Emails to Bigpond are bouncing or being marked as spam due to a combination of factors related to sender reputation, content, technical configuration, and Bigpond's infrastructure. Key issues include Bigpond's strict spam filters and sending limits, potential server overload, poor sender reputation stemming from spam complaints or blocklisting, content triggering spam filters (e.g., URLs flagged as spam, spam trigger words), and incorrect or missing email authentication protocols (SPF, DKIM, DMARC). Additionally, neglecting list hygiene, failing to warm up IP addresses, and a potentially worsening sender reputation over time (even without changes to the sending strategy) contribute to deliverability problems. Contacting Bigpond directly, reviewing bounce codes, and monitoring feedback loops are recommended actions.
Key findings
- Bigpond's Infrastructure: Bigpond's servers may have limited capacity or be nearing end-of-life, and are generally known to be strict. Their overload could lead to rejections.
- Spam Filters: Bigpond's spam filters are very sensitive, marking emails as spam for various reasons.
- Sending Limits: Exceeding Bigpond's sending limits (e.g., over 7500/h) triggers bounces.
- Poor Sender Reputation: Spam complaints, blocklistings, and sudden volume spikes negatively impact reputation.
- Content Issues: URLs flagged as spam, spam trigger words, and poor formatting trigger filters.
- Authentication Problems: Incorrect or missing SPF, DKIM, and DMARC lead to failed authentication.
- Declining Reputation: Reputation can decline even without changes to the sending strategy.
Key considerations
- Contact Bigpond: Reach out to Bigpond support for specific bounce reasons and filter sensitivities.
- Adjust Volume: Stay under Bigpond's sending limits, potentially lower than other providers.
- Monitor Bounces: Track and analyze bounce codes for insights into rejection causes.
- Implement Authentication: Set up SPF, DKIM, and DMARC correctly to authenticate emails.
- Improve Content: Avoid spam trigger words, excessive links, and ensure clean HTML.
- List Hygiene: Regularly remove inactive or invalid addresses from your email list.
- IP Warm-Up: Gradually increase email volume from new IP addresses.
- Feedback Loops: Monitor and address feedback loops to handle complaints.
- Pre-Send Testing: Test your emails before sending with spam checkers and other testing tools.
- Compliance: Adhere to email marketing best practices and CAN-SPAM regulations.
What email marketers say
10 marketer opinions
Emails to Bigpond are bouncing or being marked as spam due to several factors. These include strict spam filters and smaller sending limits, potential server volume issues, and the importance of maintaining good sender reputation. Specific actions recommended involve checking transient bounces, adjusting sending volume, contacting Bigpond support, practicing list hygiene, implementing email authentication, addressing content issues, conducting pre-send testing, personalizing emails, and monitoring reputation metrics.
Key opinions
- Sending Volume: Bigpond may have strict sending limits (e.g., under 7500/h) that, if exceeded, can cause bounces.
- Server Issues: Bigpond's servers may struggle with volume, leading to delivery problems.
- Strict Spam Filters: Bigpond's spam filters are often oversensitive and may mark legitimate emails as spam.
- Sender Reputation: A positive sender reputation is critical; factors include volume, bounce rates, spam complaints, and authentication.
- Content Issues: Spam trigger words, excessive links, and poor HTML formatting can trigger spam filters.
Key considerations
- Monitor Bounces: Regularly check transient bounces and adjust volume thresholds on mail servers.
- Contact Support: Contact Bigpond support directly to inquire about the cause of bounces and filter sensitivities.
- List Hygiene: Remove inactive or invalid email addresses to improve deliverability.
- Email Authentication: Implement SPF, DKIM, and DMARC to authenticate emails and prove legitimacy.
- Pre-Send Testing: Test email content with spam checkers and email testing tools before sending.
- Personalization: Personalize emails to increase engagement and reduce the chance of being marked as spam.
Marketer view
Email marketer from Sender.net highlights that implementing email authentication protocols (SPF, DKIM, DMARC) helps to prove that you are a legitimate sender, increasing deliverability and reducing the likelihood of being marked as spam.
1 Aug 2021 - Sender.net
Marketer view
Email marketer from Mailjet emphasizes the importance of list hygiene for deliverability. Regularly remove inactive or invalid email addresses, as sending to these addresses can increase bounce rates and negatively impact sender reputation.
11 May 2025 - Mailjet
What the experts say
3 expert opinions
Emails to Bigpond bounce or are marked as spam primarily due to poor sender reputation, triggering spam filters with URL content, and technical authentication issues. Maintaining a good sender reputation through monitoring feedback loops, addressing complaints, and adhering to email best practices are also crucial. It's also important to remember that reputation may worsen even if your email strategy remains constant.
Key opinions
- URL Content: URLs in emails might be flagged as 'seen frequently in spam,' triggering filters.
- Sender Reputation Decline: Sender reputation can worsen over time, even without changes to email strategy.
- Technical Issues: Incorrect authentication (SPF, DKIM, DMARC) can lead to bounces and spam filtering.
- Content Triggers: Email content itself can trigger spam filters.
- Sender Reputation Importance: Maintaining a good sender reputation is crucial.
Key considerations
- Review Bounce Codes: Analyze bounce codes to understand the specific reasons for email rejection.
- Improve Email Content: Refine email content to avoid triggering spam filters.
- Authentication Setup: Ensure proper implementation of SPF, DKIM, and DMARC.
- Monitor Feedback Loops: Actively monitor feedback loops to identify and address complaints.
- Proactive Complaint Handling: Proactively address complaints to maintain sender reputation.
- Email Best Practices & Regulations: Adhere to email best practices and comply with regulations such as CAN-SPAM.
Expert view
Expert from Email Geeks suggests that 'suspected spam content' could mean that the URLs are flagged as 'seen frequently in spam'. Also, just because the strategy hasn’t changed doesn’t mean the reputation hasn’t been getting worse over time.
6 Nov 2023 - Email Geeks
Expert view
Expert from Spam Resource explains that bounces and spam filtering often stem from poor sender reputation, content triggers, or technical issues like incorrect authentication. They advise reviewing bounce codes, improving email content, and ensuring proper authentication setup (SPF, DKIM, DMARC).
12 Mar 2024 - Spam Resource
What the documentation says
5 technical articles
Emails to Bigpond may bounce or be marked as spam due to several documented reasons: exceeding sending limits or triggering content-based spam filters (Telstra), poor IP reputation from spam complaints and blocklisting (Spamhaus), SMTP error codes indicating permanent policy failures (RFC), lack of DMARC policy to manage SPF/DKIM failures (Google), and failure to properly warm up IP addresses, leading to a negative sending reputation (Microsoft). These combined factors contribute to deliverability issues.
Key findings
- Sending Limits & Content: Exceeding sending limits or triggering content filters on Bigpond leads to bounces.
- Server Overload: Bigpond servers experience overload, especially during peak periods, causing temporary rejections.
- Poor IP Reputation: Spam complaints, blocklist listings, and volume spikes degrade IP reputation.
- SMTP Errors: SMTP error codes (e.g., 550) indicate policy-related or spam filtering failures.
- Lack of DMARC: Missing DMARC policy fails to instruct recipient servers on how to handle authentication failures.
- No IP Warming: Failure to gradually warm up IP addresses hurts sending reputation.
Key considerations
- Adhere to Sending Limits: Ensure email volume stays within Bigpond's defined limits.
- Optimize Content: Refine email content to avoid triggering spam filters.
- Monitor IP Reputation: Actively monitor IP reputation to detect and address issues.
- Implement DMARC: Set up a DMARC policy to manage emails failing SPF or DKIM checks.
- IP Warm-Up: Gradually increase email volume when using a new IP address.
- Review Error Codes: Analyze SMTP error codes to pinpoint specific reasons for rejection.
Technical article
Documentation from Telstra Support Website explains that Bigpond email bounces or spam issues can arise from exceeding sending limits or triggering spam filters due to content. Highlighting server overload issues during peak periods, potentially leading to temporary rejections.
6 Feb 2024 - Telstra Support Website
Technical article
Documentation from Spamhaus explains that poor IP reputation leads to email blocking and spam marking. Contributing factors include spam complaints, blocklist listings, and sudden spikes in email volume.
25 Apr 2023 - Spamhaus
