What does the Vade Secure OXSUS0001_403 error code mean and how should it be handled?

Email marketer from Email Geeks shares Vade Secure's response stating that the OXSEU0001_403 error indicates an invalid email address (non-existent user). They recommend that bulk mailers treat it as a hard bounce and remove the address from their database. If the sender is not a bulk mailer, the issue is the same: the email address is wrong.

Email marketer from Email Geeks shares the two definitions listed on Vade Secure's postmaster page for the OXSUS0001_403 error code. The first definition relates to an invalid recipient address format, and the second indicates a non-existent user, which should be treated as an unsubscribe for bulk mailers.

Email marketer from Reddit suggests that if you encounter the OXSUS0001_403 error, especially when sending to Earthlink addresses, it's likely due to Vade Secure filtering. He recommends checking your sender reputation and ensuring your email list is clean to avoid being flagged as spam.

Email marketer from Email Marketing Forum shares that the OXSUS0001_403 error often indicates a problem with the recipient's email address. The user recommends cleaning your email list to remove invalid or inactive addresses to avoid future bounces and protect your sender reputation.

Email marketer from Email Geeks shares that Vade Secure's OXSUS0001_403 error has two definitions: one for non-existent users and one for invalid recipient address formats. For bulk mail, the error indicates a non-existent user and should be treated as an unsubscribe. For non-bulk mail, it indicates a format error. Earthlink did not change their error codes, so the 403 error remains ambiguous, and they treat it as a block.

Email marketer from Email Deliverability Blog suggests that encountering the OXSUS0001_403 error frequently can negatively impact your sender reputation. She recommends implementing a double opt-in process and regularly scrubbing your email list to maintain high deliverability rates.

Email marketer from Cybersecurity Solutions Website explains that If seeing OXSUS0001_403 errors via Earthlink, best practice is to treat them as hard bounces and suppress them from future mailings. He states that you can also check the validity of the email address.

Email marketer from Mailgun states that the OXSUS0001_403 error typically means that the recipient's mailbox is unavailable. It could be due to the user not existing, the mailbox being full, or a temporary issue. Mailgun suggests verifying the recipient's email address and retrying later.

Email marketer from Quora explains that in many cases, the OXSUS0001_403 error arises when Vade Secure identifies the sender as a potential source of spam or malicious content. They suggest reviewing your email content and sending practices to ensure they align with best practices and comply with anti-spam regulations.

Expert from Spam Resource explains that seeing the OXSUS0001_403 error regularly indicates issues with list hygiene. It suggests employing methods for validating addresses at the point of signup and regularly cleaning your existing lists to minimize these bounces.

Expert from Word to the Wise suggests that 400-level errors are issues which the sender can solve, while 500-level errors require the receiver to solve. So if a bounce has 403 it is an error you can fix, by addressing why the address may be invalid. She suggests working with your provider to fix the errors and suppress the users.

Documentation from ietf.org shares 5xx errors signify a permanent failure. Though OXSUS0001_403 is not a standard SMTP response, if a receiving server returns such an error for a non-existent user or an invalid address format, the sending server should not attempt to resend the message to that recipient.

Documentation from Vade Secure explains that the OXSUS0001_403 error can mean two things: either the email was sent to a non-existent customer/user or the format of the recipient's address is invalid. The first case should be treated as an unsubscribe if the sender is a bulk mailer.

Documentation from Vade Secure API provides that OXSUS0001_403 indicates that the email address is invalid, specifically that the address does not exist. The documentation notes this is most often seen when the address has been misspelled or the user account has been closed.

Documentation from Microsoft explains that though it may not recognize the specific OXSUS0001_403 error code, the 5xx error family of permanent failures generally means the email address is bad. Microsoft suggests reviewing and removing addresses that return this error.