Summary
The inconsistent delivery of emails to Optonline.net, with some bouncing while others get through, is attributed to a complex interplay of factors. These include variable filtering techniques based on sender reputation, content, user engagement, potential greylisting or temporary blocks, inconsistent filtering rules, and common issues like poor list hygiene, blocklisting, authentication problems (SPF, DKIM, DMARC), problematic email content and rendering issues, not following the recommended google practices, and not having DMARC policies setup. Experts and marketers recommend monitoring bounce codes, improving sender reputation, practicing good list hygiene, checking blocklists, verifying email authentication, reviewing email content, using seed lists for testing, joining the Optonline feedback loop, and ensuring DMARC policies are configured to improve deliverability.
Key findings
- Variable Filtering: Optonline employs variable filtering techniques based on sender reputation, content, and user engagement.
- Inconsistent Filtering Rules: Optonline might have inconsistent filtering rules leading to some emails being delivered while others bounce.
- Greylisting/Temporary Blocks: Optonline could be using greylisting or implementing temporary blocks due to suspected spam activity.
- Reputation-Based Filtering: Low sender reputation can cause Optonline to throttle or reject emails.
- List Hygiene Issues: Poor list hygiene can lead Optonline to flag senders as spammers.
- Blocklisting Problems: Being on a blocklist can cause delivery issues with Optonline.
- Authentication Failures: Incorrect SPF, DKIM, and DMARC settings can cause Optonline to flag emails as suspicious.
- Content-Based Spam Filters: Problematic email content can trigger spam filters at Optonline.
- Rendering Issues: Rendering issues within the emails might be triggering spam filters.
Key considerations
- Monitor Bounce Codes: Regularly check and analyze bounce codes from Optonline to understand the reasons for delivery failures.
- Improve Sender Reputation: Take steps to improve sender reputation by warming up IP addresses and maintaining consistent sending volumes, ensure you are following all the google recommendations.
- Practice Good List Hygiene: Regularly clean email lists to remove inactive or invalid addresses.
- Check Blocklists: Ensure the sending IP address and domain are not on any blocklists.
- Verify Email Authentication: Confirm that SPF, DKIM, and DMARC records are correctly configured.
- Review Email Content: Audit email content for potential spam triggers, such as excessive use of certain keywords or phrases.
- Test Email Deliverability: Use seed lists to test email deliverability across different ISPs, including Optonline.
- Join Feedback Loops: Sign up for feedback loops with Optonline to gain insights into spam flagging and what they recommend.
- Ensure DMARC is setup: Ensure the correct DMARC settings are configured.
What email marketers say
9 marketer opinions
Optonline.net emails may bounce intermittently due to a combination of factors, including inconsistent filtering rules, greylisting or temporary blocks based on suspected spam activity, reputation-based filtering, poor list hygiene, blocklisting, incorrect email authentication, problematic email content, and rendering issues. Testing with seed lists can help identify specific problems.
Key opinions
- Inconsistent Filtering: Optonline may have inconsistent filtering rules, leading to variable deliverability.
- Greylisting: Optonline might employ greylisting or temporary blocks due to suspected spam activity.
- Reputation-Based Filtering: Low sender reputation can cause Optonline to throttle or reject emails.
- List Hygiene: Poor list hygiene can lead Optonline to flag senders as spammers.
- Blocklisting: Being on a blocklist can cause delivery issues with Optonline.
- Authentication Issues: Incorrect SPF, DKIM, and DMARC settings can cause Optonline to flag emails as suspicious.
- Content-Based Filtering: Problematic email content can trigger spam filters at Optonline.
- Rendering Issues: Rendering issues within the emails might be triggering spam filters leading to inconsistent delivery.
Key considerations
- Monitor Bounce Codes: Regularly check and analyze bounce codes from Optonline to understand the reasons for delivery failures.
- Improve Sender Reputation: Take steps to improve sender reputation, such as warming up IP addresses and maintaining consistent sending volumes.
- Practice Good List Hygiene: Regularly clean email lists to remove inactive or invalid addresses.
- Check Blocklists: Ensure the sending IP address and domain are not on any blocklists.
- Verify Email Authentication: Confirm that SPF, DKIM, and DMARC records are correctly configured.
- Review Email Content: Audit email content for potential spam triggers, such as excessive use of certain keywords or phrases.
- Test Email Deliverability: Use seed lists to test email deliverability across different ISPs, including Optonline.
- Feedback Loops: Ensure you're signed up for any feedback loops Optonline provide.
Marketer view
Email marketer from GlockApps suggests using a seed list to test email deliverability across different ISPs, including Optonline. This can help identify if emails are being filtered or bounced, and provide insights into the potential causes.
5 Jul 2023 - GlockApps
Marketer view
Email marketer from Twilio SendGrid discusses that the content of the emails might trigger spam filters at Optonline, especially if it contains certain keywords or phrases commonly associated with spam. This can cause some emails to be delivered while others are blocked.
15 Sep 2022 - Twilio SendGrid
What the experts say
3 expert opinions
Optonline.net emails may be bouncing inconsistently, with some emails delivering successfully while others bounce. Experts suggest this is due to variable filtering techniques employed by ISPs based on factors like sender reputation, content, and user engagement. Monitoring bounce codes and signing up for feedback loops are recommended to gain insight into Optonline's filtering processes.
Key opinions
- Variable Filtering: Optonline uses variable filtering techniques based on multiple factors.
- Simultaneous Bounces and Deliveries: Bounce issues and successful deliveries are occurring concurrently across multiple accounts.
Key considerations
- Monitor Bounce Codes: Carefully monitor bounce codes to understand the reasons for failed deliveries.
- Feedback Loops: Sign up for feedback loops with Optonline to gain insights into spam flagging.
- Adjust Sending Practices: Adjust sending practices based on bounce code analysis and feedback loop information.
Expert view
Expert from Email Geeks shares that they are seeing bounce issues across a number of accounts, but also seeing successful delivery at the same time to Optonline.net.
5 Aug 2022 - Email Geeks
Expert view
Expert from Spam Resource explains that ISPs like Optonline might use variable filtering techniques based on numerous factors (sender reputation, content, user engagement) leading to some emails being delivered while others bounce. They advise monitoring bounce codes and adjusting sending practices accordingly.
20 Nov 2022 - Spam Resource
What the documentation says
5 technical articles
Optonline.net's inconsistent email delivery, with some emails bouncing while others succeed, can be attributed to several factors outlined in email deliverability documentation. These include the SMTP error codes indicating temporary or permanent failures, the impact of sender reputation on filtering decisions, adherence to Google Postmaster Tools' best practices (spam rates, complaint rates, authentication), properly configuring DMARC policies, and properly configuring SPF records. Poor configuration in any of these areas can cause Optonline to inconsistently accept or reject emails.
Key findings
- SMTP Error Codes: Optonline uses SMTP error codes (4xx and 5xx) to signal temporary or permanent delivery failures.
- Sender Reputation: Optonline relies on sender reputation scores to determine whether to accept, reject, or filter emails.
- Google Postmaster Tools Compliance: Meeting Google Postmaster Tools' guidelines on spam rates, complaint rates, and authentication is crucial for deliverability to Optonline.
- DMARC Policy Configuration: Properly configured DMARC policies are essential for guiding Optonline's handling of emails that fail authentication.
- SPF Record Configuration: Proper SPF records are important to prevent spammers from forging emails and causing deliverability issues at Optonline.
Key considerations
- Analyze SMTP Error Codes: Analyze bounce messages and their SMTP error codes to identify the root cause of delivery failures.
- Monitor and Improve Sender Reputation: Actively monitor and improve sender reputation by adhering to best practices and engaging with feedback loops.
- Comply with Google Postmaster Tools: Adhere to Google Postmaster Tools' guidelines to maintain a positive sending reputation and ensure deliverability.
- Configure DMARC Properly: Implement and properly configure DMARC policies to protect against email spoofing and improve deliverability.
- Validate SPF Records: Ensure SPF records are correctly configured to authorize sending servers and prevent email spoofing.
Technical article
Documentation from DMARC.org outlines that DMARC policies (none, quarantine, reject) instruct receiving mail servers on how to handle emails that fail authentication checks. If a sender's DMARC policy is not properly configured, Optonline might handle those emails inconsistently.
30 Sep 2023 - DMARC.org
Technical article
Documentation from Google Postmaster Tools states the necessity to monitor spam rates, maintain low complaint rates, and authenticate emails properly using SPF, DKIM, and DMARC. Failing to meet these requirements can lead to delivery issues with ISPs like Optonline.
7 Feb 2022 - Google
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