Summary
Password reset emails blocked by Optimum/Altice can stem from several interconnected issues, making diagnosis and remediation complex. Technical problems, such as incorrect rDNS or SMTP configurations, and authentication failures with SPF, DKIM, and DMARC, are often root causes. A key factor is sender reputation, influenced by IP and domain reputation, user complaints, and engagement. Blacklisting of IP addresses, either directly or due to association with spammy content, also plays a role. The volume and consistency of email sending, particularly from new domains, affects deliverability, as does list hygiene. Furthermore, ISP-specific filtering rules, which are often opaque, contribute to the problem. To address this, consider verifying technical configurations, managing sender and domain reputation, actively monitoring blacklists, warming up new domains carefully, setting up feedback loops, validating email lists, implementing DMARC for robust authentication, and, if needed, attempting to contact the ISP's postmaster.
Key findings
- Technical Configuration: Technical errors, like incorrect rDNS and SMTP configurations, are potential causes.
- Authentication Failures: SPF, DKIM, and DMARC misconfigurations lead to deliverability problems.
- Sender Reputation: Low sender reputation is a major reason for blocks, influenced by IP and domain reputation, and spam complaints.
- Blacklisting: IP address blacklisting significantly impacts deliverability.
- Volume and Warmup: Email volume, especially from new domains, affects filtering; domain warmup is essential.
- List Hygiene: Poor list hygiene degrades engagement and deliverability.
- ISP-Specific Filtering: Optimum/Altice's specific, often opaque, filtering rules contribute to the problem.
Key considerations
- Verify Technical Configuration: Ensure correct rDNS and SMTP settings.
- Correct Authentication: Properly configure SPF, DKIM, and DMARC records.
- Manage Sender Reputation: Monitor and maintain a good IP and domain reputation, minimizing spam complaints.
- Monitor Blacklists: Actively monitor for and address blacklisting.
- Warm Up New Domains: Gradually increase sending volume from new domains.
- Implement Feedback Loops: Set up feedback loops to track spam complaints.
- Clean Email Lists: Remove inactive addresses to improve engagement.
- Contact ISP: Attempt contact with Optimum/Altice postmaster for specific guidance.
What email marketers say
10 marketer opinions
Password reset emails blocked by Optimum/Altice can stem from various issues, with sender reputation being a central factor. Blocks aren't usually Cloudmark-related but might be due to domain or IP reputation, or spam filter triggers related to content. Ensuring correct SPF and DKIM records is essential. Maintaining a good sender reputation involves consistent IP usage, domain name management, and minimizing spam complaints. Dedicated IPs offer more control over reputation. Employing double opt-in helps verify subscriber authenticity. Warming up new domains with lower email volume is recommended. Setting up feedback loops allows tracking spam complaints. Monitoring and avoiding blacklists is crucial. Improving domain reputation can be achieved by ensuring correct DNS records, avoiding spam traps, and sending desired content.
Key opinions
- Sender Reputation: Low sender reputation is a primary cause for password reset emails being blocked. Factors such as IP address reputation, domain reputation, and spam complaints significantly influence sender reputation.
- Authentication Issues: Incorrect or missing SPF and DKIM records can cause password reset emails to be blocked, therefore proper configuration is essential.
- Volume and Domain Warm-up: High email volume from new domains can trigger spam filters, therefore warming up a domain gradually is advised.
- Feedback Loops: Setting up feedback loops allows tracking spam complaints, providing valuable insights for improving email practices.
- IP Reputation Checks: IP address might be blacklisted; checking against common blacklists and requesting delisting if necessary is important.
- Dedicated IPs: Using dedicated IPs can help control sender reputation since you are isolated from other users sending practices.
Key considerations
- Monitor Blacklists: Regularly monitor your IP address and domain against common blacklists to identify and address any issues promptly.
- Improve Domain Reputation: Ensure correct DNS records, avoid spam traps, and send content that recipients want to receive in order to improve overall domain reputation.
- Content Review: Assess the content of your password reset emails to ensure it doesn't trigger spam filters. Avoid using spam-related words and ensure the content is relevant and clear.
- Contact ISP: Contacting Optimum/Altice support to ask for support.
- Double Opt-In: Make sure double opt-in is enabled when collecting email addresses.
- Consistent IP: Use a consistent IP for sending email.
Marketer view
Email marketer from TechSupportForum.com suggests a few reasons for email blocking. The marketer mentions that one reason could be the email volume from the domain. If the domain is new, it is advised to warm the domain up by starting with a lower amount of emails and increasing from there.
10 Jan 2023 - TechSupportForum.com
Marketer view
Email marketer from AuthSMTP explains to use double opt-in when collecting email addresses. Double opt-in helps by verifiying the authenticity of each subscriber.
20 Feb 2025 - AuthSMTP
What the experts say
4 expert opinions
Password reset email deliverability issues with Optimum/Altice often result from technical errors, authentication problems, and IP reputation. Possible technical errors include rDNS mismatches, SMTP misconfigurations, or incorrect authentication setups. Addressing blocks from specific ISPs is challenging due to their filtering rules' opacity. Direct contact with their postmaster might be necessary. Authentication issues like SPF, DKIM, and DMARC misconfigurations significantly impact deliverability. Maintaining a clean IP reputation through monitoring blacklists and engaging in responsible sending practices is crucial for inbox placement.
Key opinions
- Technical Errors: rDNS mismatches, SMTP misconfigurations, or incorrect authentication setups can cause password reset email blocks.
- ISP Filtering: Dealing with blocks from specific ISPs is challenging due to opaque filtering rules; contacting their postmaster is a potential solution.
- Authentication: SPF, DKIM, and DMARC misconfigurations are major factors impacting password reset email deliverability.
- IP Reputation: Maintaining a clean IP reputation is vital; a low IP reputation can hinder inbox placement.
Key considerations
- Check Technical Configuration: Ensure rDNS matches, SMTP is correctly configured, and authentication is properly set up.
- Contact ISP Postmaster: Attempt direct communication with Optimum/Altice's postmaster to understand specific filtering rules and potential solutions.
- Verify Authentication Records: Carefully verify SPF, DKIM, and DMARC records to ensure they are correctly configured and aligned with your sending infrastructure.
- Monitor Blacklists: Regularly monitor your IP address against blacklists and address any listings promptly.
- Practice Responsible Sending: Engage in responsible sending practices to maintain a healthy IP reputation.
Expert view
Expert from Email Geeks suggests there may be a technical error causing problems, such as the rDNS not matching, a weird SMTP configuration, or incorrect authentication.
29 Sep 2021 - Email Geeks
Expert view
Expert from Spam Resource explains that dealing with blocks from specific ISPs like Optimum/Altice often involves understanding their specific filtering rules, which are often opaque. The best approach is often to contact their postmaster directly, but response rates can vary.
10 Mar 2025 - Spam Resource
What the documentation says
5 technical articles
Password reset emails are blocked by Optimum/Altice for reasons that revolve around authentication, sender reputation, and list hygiene. Proper SMTP authentication, including correctly configured reverse DNS, is crucial. Maintaining a good sender reputation, monitored through bounce rates and user complaints, is essential for deliverability. Microsoft identifies new senders as a potential cause for junking, recommending addition to Safe Senders lists. DMARC is important for protecting against spoofing and phishing, signaling trustworthiness to mailbox providers. Finally, maintaining list hygiene by removing inactive addresses improves engagement rates.
Key findings
- SMTP Authentication: Proper SMTP authentication, including a matching reverse DNS, is vital to avoid being marked as spam.
- Sender Reputation: Maintaining a good sender reputation by monitoring bounce rates and user complaints is key for deliverability.
- New Sender Status: Emails from new senders can end up in the junk folder, which users can resolve by adding the sender to their Safe Senders list.
- DMARC Protection: DMARC helps protect against spoofing and phishing attacks, signaling trustworthiness to mailbox providers like Optimum/Altice.
- List Hygiene: Removing inactive addresses improves engagement rate and, consequently, deliverability.
Key considerations
- Verify Reverse DNS: Ensure that reverse DNS is correctly set up and matches the sending domain to enhance SMTP authentication.
- Monitor Bounce Rates: Actively monitor bounce rates and user complaints to identify and address sender reputation issues.
- Implement DMARC: Implement DMARC to protect against spoofing and phishing, signaling trustworthiness to mailbox providers.
- Clean Email Lists: Regularly remove inactive addresses from your email lists to improve engagement and sender reputation.
- Encourage Safe Sender Listing: Encourage recipients to add your sending address to their Safe Senders list, especially when first sending emails.
Technical article
Documentation from RFC Editor describes the importance of proper SMTP authentication to avoid being marked as spam. They explain to ensure that reverse DNS is correctly set up and matches the sending domain.
30 Nov 2023 - RFC Editor
Technical article
Documentation from Mandrill explains that maintaining a good sender reputation is key to deliverability. They explain the importance of monitoring bounce rates and user complaints, and taking action to address any issues.
14 Mar 2022 - Mandrill
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