Why am I receiving 554 PH01 bounce errors from Verizon Media Group / Yahoo?
Summary
What email marketers say11Marketer opinions
Email marketer from EmailGeek suggests reviewing email content for potential phishing triggers such as suspicious links, malware, or objectionable content that Yahoo deems unacceptable.
Marketer from Email Geeks confirms they received the same bounce message: '554 Message not allowed - [PH01] Email not accepted for policy reasons.'
Email marketer from EmailGeek suggests that the issue might stem from Klaviyo's shared IP pool having temporary problems with Verizon/Yahoo. If using Klaviyo, this could be a contributing factor.
Marketer from Email Geeks says that the issue might be related to Klaviyo IPs having temporary issues with Verizon/Yahoo, especially if using a shared IP pool. Their client's mailing was fine the next day.
Marketer from Email Geeks mentions experiencing tracking link blocks due to a mistake on Yahoo's end, with bounces occurring on a specific date and time.
Email marketer from EmailGeek advises checking website security to ensure it hasn't been breached and isn't hosting phishing pages, as linked content can trigger PH01 errors.
Email marketer from EmailGeek notes that the PH01 code can sometimes be a false positive and suggests contacting Yahoo support to check if there were any known issues on their end.
Email marketer from Stack Overflow advises ensuring emails don't contain elements commonly associated with phishing, such as misleading URLs, requests for personal information, or urgent calls to action.
Email marketer from EmailonAcid suggests that the PH01 error may indicate reputation damage that needs review. It is suggested to look into feedback loops and list hygiene.
Email marketer from EmailGeek suggests the domain in the from address may be causing the bounce, or it may be a false positive, and recommends to reach out to the postmaster team.
Email marketer from Stack Overflow advises checking the sender's domain reputation and authentication (SPF, DKIM, DMARC) settings to ensure they are properly configured and not contributing to the issue.
What the experts say5Expert opinions
Expert from Word to the Wise highlights that a damaged sender reputation, even if unintentional, can lead to increased filtering and bouncebacks like PH01. Recommends focusing on building and maintaining a positive reputation.
Expert from Email Geeks explains that PH01 is an indicator that the systems thought the message might be phishing. Recommends reviewing the content and opening a support ticket with Yahoo.
Expert from Email Geeks suggests that security folks check the website to ensure it's not breached and hosting a phishing page. Also, compromised third-party sites linked in emails or malicious uploads to CDNs can trigger phishing flags.
Expert from Email Geeks shares that PH can be a bunch of things, including viruses, phishing attempts, ransomware, other malicious software, and links or URLs to any of the above.
Expert from Spam Resource suggests carefully evaluating email content for elements that could be misconstrued as phishing attempts, including suspicious links, language, or branding that mimics legitimate institutions.
What the documentation says4Technical articles
Documentation from Senders.yahooinc.com explains that PH01 is a 'Message not allowed' error related to policy reasons and often indicates a suspected phishing attempt. It directs senders to their error codes page for more information and support ticket options.
Documentation from RFC details a 554 SMTP reply code indicates that the transaction has failed because the content of the message was determined to violate local policies, it doesn't provide the exact reason for this error and is only a top level code.
Documentation from Mailjet, explains that 'hard bounces' indicate a permanent reason an email cannot be delivered. PH01 falls into this category and warrants investigation into the content and sending practices.
Documentation from SparkPost generally explains that 5xx errors are permanent failures. While not specific to PH01, it highlights the need to investigate the specific error details provided by the receiving mail server.