Search Our Database

Introduction

When an email is bounced back with Error Code 550 and marked as SPAM, it means the recipient’s mail server has rejected the email. This is often due to content issues, improper mail server settings, or blacklisting. This guide provides simple steps to troubleshoot and fix the issue from the sender’s side.

Prerequisites

• Access to your mail server settings.
• Basic knowledge of email authentication protocols like SPF, DKIM, and DMARC.
• Tools to check blacklists (e.g., MXToolbox).

Step-by-Step Guide

Step 1: Check the Email Content

• Add more text content: Emails with too little text may be flagged as spam.
• Reduce links: Limit the number of external links, especially shortened URLs.
• Avoid spam trigger words: Words like “free,” “guaranteed,” or “urgent” can trigger spam filters.
• Minimize attachments: Large or unusual attachments might be blocked.

Step 2: Verify SPF, DKIM, and DMARC Records

Ensure your domain has the correct DNS records:

• SPF: Authorizes your mail server to send emails on behalf of your domain.
• DKIM: Adds a digital signature to your emails to prove they haven’t been altered.
• DMARC: Aligns SPF and DKIM to protect your domain from spoofing.

Use tools like MXToolbox to verify these records.

Step 3: Check for Blacklisting

Your IP or domain may be blacklisted. To check:

1. Go to MXToolbox Blacklist Check.
2. Enter your domain or mail server IP.
3. If blacklisted, follow the platform’s instructions to request removal.

Step 4: Ensure Proper Reverse DNS Setup

Make sure your mail server has a reverse DNS (PTR) record. This links your IP address back to your domain name, improving email deliverability.

Conclusion

By optimizing your email content, ensuring proper DNS configurations, and checking blacklists, you can reduce the chances of your emails being marked as spam. Regularly monitoring your email server’s reputation helps maintain reliable email communication.

Should you have any inquiries about the guidelines, please feel free to open a ticket through your portal account or contact us at support@ipserverone.com. We’ll be happy to assist you further.