Think of 4XX errors as something that didn’t go right, but may still have a chance to be delivered, later.Įmail error codes from 500-599 are bad, very bad. These codes often force the mail transfer agent (MTA) server to put the message in queue until its delivery is successful or its duration to live times out, typically the value can be anywhere between 1 and 5 days. If the same mail is sent in the future, it may be successfully delivered. The code normally comes in the report’s non-delivery-response. In this case of codes from 400-499, a message is regarded as valid in the initial state it was relayed, but a persistent temporary condition has caused delay or abortion in retrying to get the message delivered. Though it may be called an error code, when you see a 200-299 code, you’ve actually had success, and the message didn’t encounter any major issues or problems with the mail servers along the way.ĤXX (Persistent Transient/Temporary Failure) Success here means that the Delivery Status Notification (DSN) is giving a report of successful delivery. This first digit gives you some broad general information as to whether: The first number in the code is the class and it’s usually 2, 4 or 5. And the syntax of a status code is typically a 3 digit number which details more about the type of issue encountered. This guide will walk you through the most common categories of email errors that occur, how they happen, and what you can do to fix the error so your emails can be delivered again.Įmail error notifications appear in the form of status codes. Other times, you get a bounced email with an error stating that the server had some cryptic problem. Sometimes it’s something you did wrong, like mistype the email address. For a complete guide to email error codes in detail, check out our wiki.Įmail errors can happen. What are email error codes? What do email error codes mean? What can I do to overcome email errors? Get the answers to all these questions about email error codes, and more, with this straightforward, plain English explanation.