SMTP Error 517:

What does it mean? And How to resolve this error.

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Error Description

SMTP error 517 is a permanent or "5xx" error code returned by a mail server to indicate that the sender's email address has been blocked or suspended due to policy violations or other reasons. It signifies that the email server will not accept or deliver emails from the sender's address, making it a restrictive error.

What's Causing This Error?

SMTP error 517 is typically caused by one or more of the following reasons:

  • Policy violations: The sender's email address may have been flagged for sending spam, engaging in abusive behavior, or violating the recipient server's policies.
  • Blacklisting: The sender's domain or IP address may be listed on email blacklists, which are maintained to block known sources of spam or malicious emails.
  • Suspicion of phishing or fraud: The sender's email address or content may raise suspicion of phishing attempts, fraud, or other malicious activities.
  • Recipient server's security policies: The recipient's email server may have strict security policies in place that trigger SMTP error 517 for certain senders.

How to fix SMTP Error 517?

  • Contact email administrator: If you encounter SMTP error 517, the best course of action is to contact the recipient's email administrator or support team to inquire about the reason for the block and request a resolution.
  • Address policy violations: If your email address was blocked due to policy violations, ensure that you follow email best practices, including obtaining proper consent for sending emails and adhering to anti-spam laws.
  • Remove from blacklists: If your domain or IP address is blacklisted, you'll need to take steps to remove it from the blacklist(s) and improve your email reputation.
  • Verify content and intent: Review your email content to ensure it does not appear malicious or deceptive. Avoid using misleading subject lines or engaging in fraudulent activities.
  • Respect recipient server policies: Be aware of the recipient server's security policies and guidelines to avoid triggering blocks in the future.

SMTP Error Examples

Example 1: "517 5.7.1 Sender address blocked due to policy violations."

Example 2: "517 5.1.0 The sender's domain is blacklisted. Emails from this domain are not accepted."

Example 3: "517 5.2.3 Suspicion of phishing activity detected. Email delivery denied."

Example 4: "517 5.5.2 Sender's IP address has been banned for abusive behavior."

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