Is Vade's use of 550 5.7.1 a hard bounce, and what do the error codes mean?

Email marketer from MailerQ explains that although `5.7.1` often indicates an issue with anti-spam policies it's still worth checking what policies are in place before automatically classing as a hard bounce

Email marketer from Mailjet shares that a `5.7.1` error usually indicates a permanent failure and should be treated as a hard bounce. They suggest reviewing your sending practices to prevent such errors.

Email marketer from Litmus Community Forum explains that it's crucial to look at the text portion of the SMTP response for clarity and that the `5.7.1` response is a permanent failure and should be treated as a hard bounce.

Email marketer from Mailgun says that although `5xx` codes are errors and treated as hard bounces, they state that you should check all bounce messages and look at why the original message failed - the full diagnostic code as there could be different issues such as anti-spam policies.

Marketer from Email Geeks shares that they have the Vade's `550 5.7.1` code set as a hard bounce based on their documentation.

Email marketer from Reddit suggests that while `5.7.1` usually indicates a hard bounce due to security or policy reasons, it is crucial to check the full error message from the receiving server to understand the specific reason for the bounce, because sometimes it is for other reasons.

Email marketer from Stack Overflow indicates that `550 5.7.1` often means "Delivery not authorized, message refused". It's usually a permanent error so should be treated as a hard bounce.

Email marketer from GlockApps suggests that `5.7.1` is generally treated as a hard bounce. However, they emphasize that you should check the detailed response from the receiving mail server to fully understand the reason for the rejection.

Email marketer from Email on Acid explains that `5xx` errors are generally permanent failures. A `5.7.1` code can signal recipient server security policies or sender reputation problems which result in being a hard bounce.

Expert from Email Geeks explains that `_403` is Vade's internal code for `550 5.7.1` and points out that their site's URL is incorrect.

Expert from Word to the Wise notes that the `550 5.7.1` status code is highly variable. While the first number indicates it's a permanent error, the specific cause depends on the receiving server's configuration. The best course of action is to review the specific message returned along with the error code.

Expert from Email Geeks shares that Vade is making things extremely difficult by using `550 5.7.1` for every rejection, forcing people to check a webpage for explanations of their esoteric codes.

Expert from Email Geeks highlights issues with Vade using `550 5.7.1` for "user unknown", explaining that it is not clearly defined in the spec and they should be using `550 5.1.1` instead.

Expert from Email Geeks states that the ESP is wrong, as the 403 isn't an SMTP error code. The first 3 digits in an error message is the error code.

Expert from Spam Resource explains that a `550 5.7.1` error typically indicates a delivery policy violation or security restriction. They are unable to provide a more specific reason without additional context from the bounce message.

Documentation from Microsoft explains that in Exchange Server, a `5.7.1` NDR (Non-Delivery Report) often indicates a delivery restriction or security policy preventing the email from reaching the recipient. It suggests that the sender should investigate sending limits and permissions.

Documentation from IETF explains that SMTP enhanced status codes, including the `5.7.1` code, provide a standardized way to indicate permanent delivery failures related to security or policy rejection. However, the specific meaning can vary by implementation.

Documentation from Amazon Web Services explains that Amazon SES treats `5.7.1` errors as hard bounces, indicating a permanent issue. SES automatically suppresses these addresses to protect sender reputation.

Documentation from SparkPost says that a `5.7.1` response code typically indicates a permanent bounce, often due to a policy or security filter on the recipient's side, making it a hard bounce.