Demystifying SMTP Error Codes: Understanding Email Delivery Status Notifications
SMTP (Simple Mail Transfer Protocol) error codes are numerical codes generated by mail servers to indicate the status or outcome of an email delivery attempt. Understanding these codes can help diagnose and troubleshoot email delivery issues. Here's a breakdown of some common SMTP error codes: https://obrpozor.ru/viewtopic.php?f=3&t=54 https://obrpozor.ru/viewtopic.php?f=7&t=71 https://obrpozor.ru/viewtopic.php?t=77 https://obrpozor.ru/viewtopic.php?t=24 https://obrpozor.ru/viewtopic.php?t=58 https://obrpozor.ru/viewtopic.php?t=84 1. 5xx Series (Permanent Failure): 550 - Requested action not taken: The mailbox is unavailable: This error indicates that the recipient's email address does not exist or is invalid. The email cannot be delivered, and the sender should double-check the recipient's address. 554 - Transaction failed: This error is a general failure message indicating that the email delivery transaction has failed for some reason. It could be due to issues s...