SMTP error 547 signifies your email was rejected due to problems with the recipient's email address or domain. This permanent error (5xx) indicates the recipient server couldn't deliver the message due to recipient information issues. This can occur in applications like phpmailer and jenkins when sending emails.

What are the cases covered in SMTP Error 547?

Common scenarios triggering SMTP Error 547:

1. Nonexistent Recipient: The "RCPT TO" command or "To:" field in your email contains an invalid recipient address that doesn't correspond to a real account or mailbox (phpmailer, jenkins).
2. Invalid Recipient Domain: The recipient's email domain (e.g., example.com) is non-existent, expired, or has DNS (Domain Name System) problems.
3. Unauthorized Recipient: The recipient's domain or address cannot receive your email, or it's blocked by their server for policy reasons.
4. Content Filtering: The email content might contain prohibited elements like spam, malware, or violations of the recipient server's policies.

What’s Causing This SMTP Error 547 In Your Servers?

Potential causes of SMTP Error 547:

• Incorrect Recipient Address: Double-check that the recipient's email address is spelled accurately, complete, and belongs to a valid account or mailbox (phpmailer, jenkins).
• Recipient Domain Issues: Verify that the recipient's email domain is functioning correctly, has no DNS issues, and isn't experiencing policy-based blocks.
• Contact Recipient Administrators: If the recipient's domain has issues, their administrators might need to intervene to resolve technical problems or adjust email acceptance policies.
• Revise Email Content: Address any potential policy violations in the email message, such as removing spammy content or harmful attachments, to comply with the recipient server's policies.

How to Resolve SMTP Error 547 - Step-by-Step Solution

1. Verify Recipient Address: Ensure the recipient's email address is spelled correctly, complete, and belongs to a valid account or mailbox (phpmailer, jenkins).
2. Check Recipient Domain: Confirm that the recipient's email domain is functioning correctly, has no DNS issues, and isn't experiencing policy-based blocks.
3. Contact Recipient Administrators: If the recipient's domain has issues, their administrators might need to intervene to resolve technical problems or adjust email acceptance policies.
4. Review Email Content: Analyze the email message for potential policy violations, such as spammy content or harmful attachments, and ensure it complies with the recipient server's policies.

SMTP Error 547 Examples

• "547 5.1.1 recipient@example.com: Recipient address does not exist."
• "547 5.4.5 recipient@example.com: Domain name not found. Check recipient domain."
• "547 5.7.0 recipient@example.com: Unauthorized recipient. Email blocked due to policy reasons."
• "547 5.1.2 Content filtering detected prohibited content in the email message. Delivery denied."

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