What Does Error 550 Mean? (And How Can You Resolve It?)

You’ve sent an important email, only to have it bounce back with a cryptic message. What does ‘error 550’ even mean, and more importantly, how can you resolve it?

A 550 error message is a common email problem that can disrupt your work and leave you wondering what went wrong.

In this step-by-step guide, I’ll explain Error 550 and list some ways to resolve it. The goal is to share straightforward, easy solutions so you can get back to your business without the headache of email issues.

What Does 550 Error Message ‘Permanent Block’ Mean?

An error 550 message typically appears when a recipient’s email server has rejected the email you attempted to send. It’s a permanent block, which means the server has refused to deliver your email due to an issue. These issues might range from typos in the email address to larger problems like blacklisted IP addresses.

What Causes Email Error 550?

Many factors can trigger email error 550. I’ll list some common causes and break down the associated sub-errors you might see on your screen.

Email Error 550 5.1.0 Address Rejected

One of the most common reasons for encountering a 550 error is an incorrect email address. The “5.1.0 Address Rejected” error indicates that the recipient’s server couldn’t find the specified email address.

The ‘Address rejected’ error could be due to a typing error or the recipient’s email address not existing at all. 

Email Error 550 5.7.1 Access Denied

The “5.7.1 Access Denied” error typically means that your email server has failed to authenticate properly with the recipient’s server. This error often occurs when the server believes your email might be spam or if there are authentication issues with your email host. 

‘Access denied’ can show up when you use common spam words such as ‘you have won money or a lottery,’ have email content with excessive exclamation marks, or any other actions that trigger spam filters. Check out this guide where we share tips to avoid email going to spam.

Email Error 550 5.7.0 Message Size Violation

Another potential trigger for a 550 error is exceeding the recipient server’s allowed message size. The “5.7.0 Message Size Violation” error means that your email, including any attachments, is too large for the recipient’s server to process. 

For instance, if you add a file that is 30MB in size but the recipient’s email service allows for 25 MB, you can get this error. 

Other Common Causes

Beyond these specific sub-errors, here are other common reasons for 550 errors:

1. Blacklisted IP Address: If the IP address of you email server gets blacklisted, your emails will be rejected by the recipient’s server.
2. Poor Sender Reputation: A low sender reputation can cause the recipient’s server to reject your emails. Switch to a trusted email provider service.
3. Improper DNS Settings: Misconfigured DNS settings can lead to email rejections.
4. Server Misconfiguration: If your email server isn’t properly configured, the recipient’s server might flag it.

Now that we understand the reasons behind error 550, let’s move on to how you can resolve it.

How To Fix Error 550: Eight Easy Solutions

Check For Email Address Typos

One of the simplest fixes is to double-check the recipient’s email address. Even a small typo can lead to a 550 error. Some help forums have mentioned ensuring there are no special characters or extra spaces in the ‘To’ field.’

Try Sending The Email After Some Time

Sometimes, the issue can be temporary. The recipient’s server could be experiencing high traffic or be under maintenance. Wait for a few minutes or hours and retry sending the email.

Check Whether Your Email IP is Blacklisted

Use online tools such as mxtoolbox (screenshot above) to know if your IP address is blacklisted. If it is, follow the necessary steps to delist your IP. The process typically involves contacting the blacklist administrator and providing justification for removal.

Try Changing Your Outgoing Mail Port

Your email client typically uses port 25 for sending emails. However, some ISPs block this port to reduce spam. Try changing your outgoing mail port (SMPT which stands for simple mail transfer protocol) to 587 or 465, which are commonly used alternatives. 

Check out this free guide to understand SMTP, IMAP, and POP3 ports better.

Scan for Malware on File Uploads

Malware can corrupt your email attachments and trigger a 550 error. Use antivirus software to scan your files before attaching them to your email. This simple step will ensure your email is clean and safe to send.

Contact Your ISP

If you’ve tried the above solutions and still encounter the error, contact your Internet Service Provider (ISP). They can check whether the issue is with their network and offer potential solutions.

Use A Reliable Email Hosting Service

If you’re frequently getting such email errors, it might be time to switch to a more reliable email hosting service. Services like NameHero’s Business Email Hosting offer robust features and security measures that can help minimize email delivery issues.

Improve Your Sender Reputation

Always follow the best practices for email marketing. Avoid sending bulk emails without proper opt-ins, and regularly clean your email list to remove inactive or invalid addresses. 

Improving your sender reputation can significantly reduce the chances of encountering a 550 error.

Conclusion: Final Thoughts

Error 550 might seem complex when it shows up on your screen, but it’s really not. I hope that this article helped you resolve any error 550 issues that you’re facing. Whether it’s correcting an email typo, scanning for malware, or changing your mail port, you can easily fix the problem and minimize disruptions to your email communications.

For a more robust and reliable email experience, consider exploring NameHero’s Business Email Hosting service. Our hosting plans are already trusted by thousands of businesses worldwide, so grab some launch deals on our business email plans. 

With our state-of-the-art features and top-notch email security, you can focus on what matters most—growing your business. Click here to learn more!