How to resolve email delivery issues with Cox, Optimum, and Charter/Spectrum?

Marketer from Email Geeks clarifies that at Cox, it's not necessarily IPs being blocked, but reputation being assessed across different metrics. They advise reducing sending volume/IPs if hitting limits and offer to investigate with provided IPs and rejection messages.

Marketer from Email Geeks explains that Cox's filtering is a dynamic set of rules/policies where an IP can change state during an SMTP transaction. Suggests submitting issues via the Cloudmark support form, including rejection messages, timestamps, sending IPs, and destination network/domain.

Marketer from Email Geeks shares that Cloudmark is used for spam filtering by those domains and suggests opening a ticket at Cloudmark support. They mention that maintaining low spam trap and complaint numbers usually prevents issues.

Email marketer from Litmus shares that segmenting your email list based on engagement and subscriber behavior is crucial. Sending relevant content to engaged subscribers improves your sender reputation and deliverability rates.

Email marketer from EmailonAcid highlights the value of testing your emails with different email clients and devices before sending. Testing helps you to identify and fix content-related issues that may trigger spam filters or render poorly on certain ISPs.

Email marketer from SenderScore points out that maintaining a good sender reputation is crucial. Monitoring your Sender Score and addressing any issues that negatively affect your score (such as high complaint rates or being blacklisted) can improve delivery rates across all ISPs.

Email marketer from Mailjet highlights the importance of authentication (SPF, DKIM, DMARC), list hygiene (removing invalid addresses), and avoiding spam triggers (content and sending frequency) to improve email deliverability to ISPs like Cox, Optimum, and Charter/Spectrum.

Email marketer from StackOverflow explains the necessity of having a reverse DNS (PTR) record that maps your sending IP address back to your domain name. Many ISPs, including those mentioned, use rDNS as a factor in determining sender legitimacy.

Email marketer from Reddit suggests gradually warming up new sending IPs by starting with low volumes to engaged subscribers and gradually increasing volume over time. This builds a positive sending reputation and avoids triggering spam filters at ISPs.

Email marketer from GMass warns to avoid using spam trigger words in your email subject lines and body content. Also avoid excessive use of capital letters, exclamation points, and links as these all increase risk of being flagged as spam.

Expert from Word to the Wise, Dennis Dayman, answers that setting up and monitoring feedback loops (FBLs) from ISPs is crucial for identifying and addressing deliverability issues. FBLs provide valuable data on complaints and abuse reports, allowing senders to quickly remove problematic subscribers and improve their sending reputation with ISPs like Cox.

Expert from Spam Resource, Steve Jones, emphasizes the importance of maintaining clean email lists to avoid hitting spam traps. Regularly cleaning your list to remove invalid or inactive addresses helps ensure that you are only sending to engaged recipients, reducing the likelihood of being flagged as spam by ISPs like Cox.

Expert from Word to the Wise, Laura Atkins, explains the benefits of using seeded testing to monitor deliverability across various ISPs. Seeded testing helps identify placement issues, authentication problems, and other factors impacting inboxing rates at specific providers like Cox, Optimum, and Charter/Spectrum.

Documentation from Spamhaus details how to check if your IP address is on their blocklist and what steps to take to delist if you have been listed. Monitoring and quickly addressing any listing on Spamhaus can prevent deliverability problems.

Documentation from Google advises bulk senders to authenticate their email with SPF, DKIM, and DMARC. It also suggests monitoring sender reputation via Google Postmaster Tools and following best practices for list management and sending frequency to avoid delivery issues with ISPs.

Documentation from Microsoft outlines sending limits for Outlook.com. Staying within these limits and following best practices for email sending can help avoid deliverability issues with ISPs who monitor Microsoft's blocklists.

Documentation from DMARC.org details the importance of implementing DMARC to protect your domain from email spoofing. DMARC builds upon SPF and DKIM to provide instructions to receiving mail servers on how to handle emails that fail authentication checks.

Documentation from RFC Editor specifies that SPF (Sender Policy Framework) records in your DNS zone should accurately list all authorized sending sources for your domain. Incorrect or incomplete SPF records can lead to delivery problems with ISPs that check SPF, like Cox.