Understanding common SMTP errors can help in troubleshooting issues with email delivery. Some common errors include:
550 Error: This indicates that the recipient's email address is not valid or the email server is rejecting the message. 451 Error: This indicates a temporary issue with the server, such as being overloaded or down for maintenance. 530 Error: This indicates an authentication issue, meaning the server requires authentication before sending emails.
Resolving these errors involves checking the email addresses, ensuring the SMTP server is operational, and verifying authentication credentials.