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SMTP error codes:
‍Complete lists, error description and solutions

What is an SMTP error code?

SMTP, or Simple Mail Transfer Protocol, is the standard protocol for sending and receiving email messages. SMTP error codes are three-digit numerical codes generated by email servers to communicate the status of email deliveries or to report issues encountered during the email transmission process.

These error codes play a crucial role in diagnosing and troubleshooting email-related problems. Below, you'll find a comprehensive list of SMTP error codes, along with detailed descriptions and recommended solutions to resolve them.

List of SMTP error codes

Click on each error code to learn more about its description, common root causes, and suggested solutions:
SMTP Error 533:
SMTP Error 534:
SMTP Error 535:
SMTP Error 538:
SMTP Error 540:
SMTP Error 541:
SMTP Error 542:
SMTP Error 543:
SMTP Error 546:
SMTP Error 547:
SMTP Error 551:
SMTP Error 553:
SMTP Error 555:
SMTP Error 556:
SMTP Error 450:
SMTP Error 511
SMTP Error 510:
SMTP Error 449:
SMTP Error 447:
SMTP Error 446:
SMTP Error 442:
SMTP Error 441:
SMTP Error 432:
SMTP Error 431:
SMTP Error 422:
SMTP Error 421:
SMTP Error 420:
SMTP Error 504:
SMTP Error 503:
SMTP Error 502:
SMTP Error 500:
SMTP Error 458:
SMTP Error 455:
SMTP Error 453:
SMTP Error 452:
SMTP Error 554:
SMTP Error 552:
SMTP Error 550:
SMTP Error 530:
SMTP Error 523:
SMTP Error 517:
SMTP Error 501:
SMTP Error 454:
SMTP Error 451:
SMTP Error 500:
SMTP Error 458:
SMTP Error 455:
SMTP Error 453:
SMTP Error 452:
SMTP Error 554:
SMTP Error 552:
SMTP Error 550:
SMTP Error 530:
SMTP Error 523:
SMTP Error 517:
SMTP Error 501:
SMTP Error 454:
SMTP Error 451:
SMTP
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