Why is Yahoo blocking my emails with TSS04 error?

Email marketer from EmailGeeks mentions that the content of the email, including links, images, and text, can trigger spam filters. If the content is similar to spam or contains suspicious elements, Yahoo may block the email with a TSS04 error.

Email marketer from Reddit explains that a common cause for TSS04 errors is improper DNS configuration, particularly with the domain's MX records or reverse DNS records. This prevents Yahoo from verifying the sender's server.

Email marketer from Reddit explains the use of spam trigger words or phrases or deceptive subject lines can cause Yahoo to block emails with a TSS04 error. Avoiding such tactics improves deliverability.

Email marketer from Email Marketing Forum suggests that sudden increases in email volume can trigger Yahoo's spam filters, resulting in a TSS04 error. It's important to gradually increase sending volume, especially when using new IPs or domains.

Email marketer from Reddit shares that incorrect or missing email authentication records (SPF, DKIM, DMARC) can lead to Yahoo blocking emails with a TSS04 error. Yahoo uses these records to verify the legitimacy of the sender.

Email marketer from Email Marketing Blog suggests using a dedicated IP address to build a positive reputation with Yahoo, especially for high-volume senders. Shared IPs can be affected by the actions of other users, leading to unexpected blocks.

Email marketer from Marketing Land advises segmenting email lists and tailoring content to specific audiences. Sending irrelevant content to a large number of recipients can increase spam complaints and trigger blocks like TSS04.

Email marketer from Stack Overflow answers questions about using a new IP address needing a gradual increase in email volumes to build a reputation. Rapidly sending large volumes of emails from a new IP can cause it to be flagged as spam, resulting in TSS04 errors.

Email marketer from Stack Overflow mentions that a newly assigned IP address or one that has previously been used for spam can cause TSS04 errors. It's crucial to ensure the IP has a clean reputation before sending emails to Yahoo.

Marketer from Email Geeks likens using unknown lists to carrying an unknown item onto a plane, which can lead to problems with Yahoo (the airline).

Expert from Email Geeks states that the described sending behavior sounds like normal spammer behavior, and if recognized as such by Yahoo, there might not be much that can be done to get mail delivered on an ongoing basis.

Expert from Spam Resource emphasizes that sender reputation is critical for Yahoo delivery. Factors like spam complaints, blacklistings, and low engagement rates can negatively impact reputation and lead to TSS04 errors. Actively monitoring and managing reputation is essential.

Expert from Word to the Wise explains that to diagnose TSS04 errors, you need to check the full bounce message, identify which server rejected the mail, and understand the specific reason for the rejection. This may involve looking at DNS issues, reputation problems, or content filters.

Expert from Email Geeks explains that if you don’t control or influence how email addresses are acquired and their lifecycle … you’re not doing deliverabilty; at best you’re doing filter evasion.

Expert from Email Geeks explains that delivery is dominated by sending mail people like to receive to people who are expecting to receive it. Technical details are important but not as impactful once the basics are in place.

Expert from Email Geeks explains that the most likely cause of delivery problems is that Yahoo has noticed the sender's patterns, noticed that their customers complain about the mail, and is therefore blocking it. The only real fix is to stop the practices that are causing Yahoo to see the mail as spam.

Expert from Word to the Wise highlights that poor list hygiene practices, such as sending emails to inactive or invalid addresses, can negatively impact sender reputation and lead to delivery issues, including TSS04 errors with Yahoo. Regular list cleaning and validation are important.

Documentation from Google Postmaster Tools explains that low engagement metrics and high spam complaints can negatively impact sender reputation with various ISPs, including Yahoo, leading to blocks and errors like TSS04.

Documentation from SparkPost explains that sending emails to spam traps can severely damage sender reputation and result in blocks like TSS04 errors. Maintaining clean lists and practicing proper list hygiene is essential.

Documentation from MailerQ indicates that a TSS04 error can also occur when the sender's IP address or domain has a poor reputation, which leads to Yahoo Mail blocking the email. This can be triggered by spam complaints or being listed on blocklists.

Documentation from Yahoo Help Central explains that the error message 'TSS04 DNS resolution error' or similar usually means there's a problem with the sender's DNS configuration, causing Yahoo Mail to reject the email. It indicates that Yahoo's servers were unable to properly resolve the sending server's domain name.

Documentation from Microsoft Support explains that sender reputation plays a crucial role in email delivery. If Yahoo perceives the sender's domain or IP as having a low reputation due to various factors like spam complaints, they are likely to block the emails with a TSS04 error.