Cara Memperbaiki Kesalahan Email “550 No Such User Here”

Encountering a “550 No Such User Here” error when sending an email indicates that the recipient’s mail server cannot locate the specified email address. This frustrating issue can stem from various causes, each requiring a specific troubleshooting approach.

This guide explains what triggers this error, how to identify the root cause, and the steps you can take to resolve it.

Understanding the Error

Before diving into solutions, it helps to understand what’s actually happening when you see this error.

When you send an email, your message travels from your mail server to the recipient’s mail server. The recipient’s server then checks whether the email address you’re sending to actually exists. If it can’t find that address, it rejects the message and sends back a “550 No Such User Here” bounce notification.

Important: This error can occur in two different scenarios:

1. You sent an email and received a bounce-back. The recipient’s server rejected your message because it couldn’t find the address you sent to.
2. You received a bounce-back for an email you never sent. Someone may be “spoofing” your email address (using it as a fake return address for spam). When those spam emails bounce, the error messages come to you. In this case, there’s unfortunately little you can do since the problem originates from someone else misusing your address.

Understanding which scenario applies to you will determine whether you can fix the issue or need to contact someone else for help.

Recognizing the Error

This error can appear in several different forms depending on the mail server. If you see any of the following messages, you’re dealing with the same underlying issue:

• 550 No Such User Here
• SMTP Error 550
• 550 Invalid recipient
• 550 User account is unavailable
• 550 Requested action not taken: mailbox unavailable
• 550 Address rejected
• 550 Recipient not found
• 550 Mailbox does not exist
• 550 User unknown
• 550 Not our customer

The “550” code specifically indicates a permanent delivery failure, meaning the server won’t attempt to resend the message automatically.

Common Causes of the “550 No Such User Here” Error

1. Incorrect Email Address

The most common cause is simply a typo in the recipient’s email address. Even minor errors like a misplaced letter, an extra character, or an incorrect domain can prevent successful delivery.

2. Non-Existent Email Account

The recipient’s email account may have been deleted, deactivated due to inactivity, or may never have existed in the first place. This often happens when someone provides an incorrect email address or when a company changes email systems.

3. Misconfigured Mail Exchange (MX) Records

MX (Mail Exchange) records are DNS settings that tell the internet which server handles email for a domain. Think of them as a postal address for emails—they direct messages to the correct mail server.

If the domain’s MX records point to the wrong server (common after website migrations or hosting changes), emails may not reach their intended destination.

4. Email Routing Issues

Email routing determines whether your server handles mail locally or forwards it to another server (like Google Workspace or Microsoft 365).

A common scenario: After migrating a domain to a new host, the email routing may be incorrectly set to “Local” when the email service actually remains with the previous provider. The local server looks for the user but can’t find them because the mailbox exists elsewhere.

The reverse can also occur where routing is set to “Remote” but the email accounts haven’t been created on the external service.

5. File Permission Errors

On hosting servers, file permissions control who can read and write specific files. If permissions are set incorrectly, the mail server may not be able to access the configuration files it needs to verify email accounts, resulting in delivery errors.

6. Email Forwarders or Alias Misconfiguration

If you’ve set up email forwarders or aliases, misconfiguration can trigger this error. A forwarder pointing to a non-existent address, or an alias that wasn’t properly created, will cause the server to report that the user doesn’t exist.

7. Catch-All Address Changes

A catch-all email address receives messages sent to any address at your domain, even if that specific mailbox doesn’t exist. If a domain previously had a catch-all configured and it was removed, emails to non-existent addresses will now bounce with this error instead of being collected.

8. Domain Migration Issues

When domains are migrated between hosting providers, “phantom” entries can remain on the old server. If the old server still thinks it handles email for your domain, it may intercept messages and return errors because the accounts no longer exist there.

9. Empty Email Content

Some mail servers reject emails that have no content in the body. While less common, sending a completely blank email can trigger rejection.

10. Blocked Outgoing Ports

Port 25, the traditional SMTP port, is often blocked by internet service providers to prevent spam. If your outgoing mail can’t connect properly, you may receive various delivery errors.

Steps to Resolve the Error

Step 1: Verify Both Email Addresses

Start with the basics:

• Check the recipient’s address for typos, extra spaces, or special characters
• Verify the domain is spelled correctly (e.g., gmail.com vs. gmial.com)
• Confirm with the recipient that the email account is still active
• Check your sender address to ensure it’s correctly configured in your email client

Step 2: Check MX Records

Use a DNS lookup tool to verify that the domain’s MX records point to the correct mail server.

How to check:

1. Visit a DNS lookup tool (such as MXToolbox or DNS Checker)
2. Enter the domain name (the part after the @ symbol)
3. Look for MX records and verify they point to the expected mail server

If the MX records are incorrect (common after hosting migrations), you’ll need to update them in your domain’s DNS settings. This is typically done through your domain registrar or hosting control panel.

Step 3: Review Email Routing Settings

If you use cPanel, check your email routing configuration:

1. Log in to cPanel
2. Navigate to Email Routing (under the Email section)
3. Select the appropriate domain
4. Verify the routing is set correctly:
   • Local Mail Exchanger — Choose this if your current hosting server handles email for this domain.
   • Remote Mail Exchanger — Choose this if an external service (like Google Workspace, Microsoft 365, or another hosting provider) handles your email.

Common mistake: After migrating a website to new hosting, the email routing gets set to “Local” even though email is still handled by the previous provider or a third-party service.

Step 4: Check Email Forwarders and Aliases

In cPanel, review your forwarders and aliases:

1. Navigate to Forwarders (under the Email section)
2. Check that all forwarders point to valid, active email addresses
3. Remove or update any forwarders pointing to non-existent addresses
4. Navigate to Email Accounts and verify aliases are correctly configured

Step 5: Verify the Email Account Exists

If you’re receiving this error for emails sent to your own domain:

1. Log in to cPanel
2. Navigate to Email Accounts
3. Confirm the email address exists and is active
4. If it doesn’t exist, create it

Step 6: Inspect File Permissions

Incorrect file permissions can prevent the mail server from functioning properly.

For cPanel users on shared hosting: Contact the InMotion Hosting support team to check and reset mail-related permissions.

For VPS or Dedicated Server users with SSH access: Run the following command to reset permissions for a cPanel account:

fixperms username

fixperms username

Replace username with the actual cPanel username. This resets folder permissions to 755 and file permissions to 644.

Note: If you’re receiving this error when sending to someone else’s server, and it’s permissions-related on their end, you’ll need to ask the recipient to contact their hosting provider.

Step 7: Try Alternative Outgoing Ports

If you suspect port blocking issues:

1. Open your email client’s account settings
2. Locate the outgoing (SMTP) server settings
3. Try changing the port from 25 to one of these alternatives:
   • Port 587 — Standard submission port (recommended)
   • Port 465 — SSL/TLS encrypted SMTP
   • Port 26 — Alternative port used by some hosting providers

Step 8: Test from a Different Email Account

To isolate the problem, try sending the same email from a different email account or provider. If the message goes through successfully, the issue likely lies with your original sending account’s configuration.

Step 9: Contact the Recipient’s Email Administrator

If you’ve verified everything on your end and the error persists, the problem may be with the recipient’s mail server. Reach out to the recipient through an alternative method (phone, social media, or a different email address) and ask them to:

• Confirm their email address is correct and active
• Check with their email administrator or hosting provider
• Verify their server isn’t experiencing technical issues

Preventive Measures

Maintain Updated Email Lists

Regularly review and clean your contact lists to remove:

• Email addresses that consistently bounce
• Contacts who have changed jobs or domains
• Inactive or deprecated addresses

Configure DNS Settings Correctly

After any hosting migration or domain transfer:

• Verify MX records point to the correct mail server
• Confirm email routing matches your actual email hosting setup
• Test email delivery to and from the domain

Monitor Email Forwarders

Periodically review all email forwarders to ensure:

• Destination addresses are still valid
• Forwarders aren’t creating loops
• Old or unused forwarders are removed

Document Your Email Configuration

Keep a record of:

• Which server handles your email
• MX record values
• Email routing settings
• Active email accounts and forwarders

This documentation makes troubleshooting much easier when issues arise.

Set Up Monitoring

Consider implementing email monitoring to catch delivery issues early. Many hosting providers offer email delivery reports that can alert you to problems before they affect critical communications.

When to Contact Support

Contact your hosting provider’s support team if:

• You’ve followed all troubleshooting steps without success
• You don’t have access to DNS settings or cPanel
• You need help interpreting server logs or error messages
• The issue affects multiple email accounts on your domain
• You suspect a server-level configuration problem

When contacting support, provide:

• The exact error message you’re receiving
• The email addresses involved (sender and recipient)
• When the problem started
• Any recent changes to your hosting, domain, or email settings

Summary

The “550 No Such User Here” error indicates that the recipient’s mail server cannot find the email address you’re trying to reach. While the error message is straightforward, the underlying causes range from simple typos to complex server misconfigurations.

Start with the basics by verifying the email address is correct and the account exists. Then work through DNS settings, email routing, and server permissions as needed. Understanding whether the issue originates from your server or the recipient’s will help you direct your troubleshooting efforts appropriately.

By systematically addressing each potential cause and implementing preventive measures, you can resolve this error and maintain reliable email delivery.