Knowledgebase

How to Fix Email Deliverability Problems

MX records, short for mail exchange, are what direct the emails sent to your domain name to the proper place. These records are usually provided by your email provider, but sometimes you will need to add the proper MX records and A records before your email will function.

 

Further reading:

Email Error Messages - What Do They Mean and How to Fix Them

Email Problems: What Should I do?

Email basics

Email settings in cPanel

 

You will need to get the records from your email provider. Once you have the MX records, please follow these steps to add them to your DNS:

 

How to add MX records to DNS

  1. Log in to your secured cpanel account.
  2. Click on Manage DNS Records in the DNS column. 
  3. In the drop-down menu under Type, select MX.
  4. Host is generally left blank, but if your host has specified that you need to add something here please do so. Please note that we do not use the @-sign (@ is a substitute for blank)
  5. Fill in the Answer field. This is generally the mail server that is redirecting your mail.
  6. Fill in the TTL and Priority fields. By default, these will be set to 300 and 10 respectively. If you are not sure what to enter here you can generally leave them alone.
  7. Click Add Record after creating each record your email provider gave you.
 
Further reading:
 
How to Solve Email Bounce Back Issues
 
How to configure Email Client
 
How to fix error 550 no such user here

 

 

Note: If you have multiple MX records, they cannot all have the same priority.

Once the records are created, the domain should successfully point to the email server within a few hours.

The reasons for the 550 email errors range from a non-existing email account to a wrongly added email server rule. To rectify the error, first, we have to analyze the basic process behind every email communication. While sending an email, it is routed from the server email to the receiver email server. Later the recipient downloads the email from his email server. So the error happens during this email delivery process which is either driven by the sender or by the receiver. We will now discuss the error ‘550-Unrouteable address’ and its solution.

 

Further reading:

Email Error Messages - What Do They Mean and How to Fix Them

Email Problems: What Should I do?

Email basics

Email settings in cPanel

 

The Causes of the Error ‘550-Unrouteable Address’

While sending an email via Outlook or webmail, in the bounce message, the error message ‘550-Unrouteable address’ is displayed. We can track the source of the error from the complete bounce message. Understanding the causes for the error, help us to make the right resolution for the error.

 

Sending Emails to a Non-Existent Recipient Domain

When the email is delivered to a non-existing recipient domain, it shows a ‘550-Unrouteable address’ error. Another reason for the error is when the user sends an email with a wrong typo in the email address. In such cases, the email reaches an invalid email address. Configuration errors in email server also cause errors, you can choose any remote server management company like Ideamine to keep your server error-free.

Sending emails to a deleted, deactivated, and expired email domain also causes ‘550-Unrouteable address’ error. So if the recipient email addresses are wrong, the emails would not be delivered and would bounce back to the sender by giving an error message.

The solution here is to validate the recipient email address while sending the emails and check whether the domain is neither expired nor deactivated.

 

Further reading:
 
How to Solve Email Bounce Back Issues
 
How to configure Email Client
 
How to fix error 550 no such user here

Incorrect MX Records for the Recipient Domain

The sender email server will not be able to route correctly to the recipient email server unless the MX records are set properly for the recipient domain. If there is any error in the DNS settings for the recipient domain, the other external emails servers render the email delivery as unreachable. The temporary DNS resolution issues with the sender’s ISP make it difficult to resolve the domain of recipient correctly which lead to the failure of email routing. So it gives rise to the bouncing back of emails and thereby the ‘550-Unrouteable address’ error is displayed.

So as a solution, always verify whether the MX records are correctly set for the recipient or not.

Always try to connect to the port 25 of the recipient email server and confirm that the connectivity is fine.

Contact the recipient server support, if you find any connectivity issues to remote email server or DNS errors or missing of MX records and get it fixed.

 

Further reading:

Email Error Messages - What Do They Mean and How to Fix Them

Email Problems: What Should I do?

Email basics

Email settings in cPanel

 

Security Constraints

Many email servers will not accept emails from the senders whose email server is in any spam blacklist. Services like Amazon SES might help you to land your emails in inbox. There are email servers which accept emails only from grey-listed senders. In RDNS security checks, it is mandatory that the server IP and its hostname have to map with each other. In order to route the IP address to the sender server name, a PTR record is set. If the sending address PTR record is not matching with the receiving address, some servers will reject the email. If the recipient server can’t verify the sender properly, the email bounces back and thus displays the error.

As a solution for this, the RDNS for the sender email server IP is should be set properly.

Through checking the spam blacklist and confirming with the remote email server, the rejections or blacklisting from the recipient email server can be confirmed. In order to secure the server in case of the blacklisting, scan the server and remove all spamming scripts and implement security measures. Check whether all the email scripts are configured with the valid sender and recipient email addresses. Thus, we can avoid sending emails to invalid addresses.

 

Further reading:
 
How to Solve Email Bounce Back Issues
 
How to configure Email Client
 
How to fix error 550 no such user here

 

Configuration Settings of Email Server

In email server such as Exim, the number of emails a domain can send out every hour has a limit. After the limit exceeds, the emails would bounce back to the sender by displaying the error ‘550-Unrouteable address’. The wrong routing of the domain can also cause the display of the ‘550- Unrouteable address’. The firewalls and other security rules in recipient email server too become a reason for the error. These scenarios are capable of generating the error ‘550- Unrouteable address’.

 

About MX Records

MX Entries are special DNS Server records that designate recipient email servers for your domain. MX Records are the resource entries in your domain’s DNS, which transmit email server information to other DNS Servers on the web, which then send emails to your domain. You can change the MX Records after creating all of the user accounts and email addresses in your cpanel settings.

Initially, it might be a good idea to set up a temporary catch all email address to avoid missing any emails. Once you have verified the creation of every account, you can change the MX Records of your domain.

 

Multiple MX Records - Why and How they work:

Multiple MX records do not deliver emails to multiple servers. Regardless of the number of records you've configured, emails are delivered to the MX record with the lowest priority as returned by your domain's DNS server. In case the lowest priority is offline or not accepting emails, only then the next server will be used.

Additional MX servers are either a redundancy for backing up MX Records, or for service administrators to make architecture and configuration changes.

 

Further reading:

Email Error Messages - What Do They Mean and How to Fix Them

Email Problems: What Should I do?

Email basics

Email settings in cPanel

 

Troubleshoot Email Delivery

Unable to receive emails even after changing MX Records:

You will start receiving emails only if the MX records are correctly configured. If you have added the MX records but are still unable to receive emails, check the following:

  • Check your domain's MX records in cPanel
  • The MX records that should match those you will find in your welcome email or you contact customer support to either resend the email or the correct MX records.

Based on the data center (US/ UK/ CN), the MX record values will differ for your domain. The correct MX records specific for your domain will be available in Control Panel. 

  • If there are other MX entries with lower priority (ex: 0 or 5), emails will not be delivered to Mail.
  • Ensure that you have deleted all other MX records related to your previous email provider.
  • Ensure that you have turned off 'Local email delivery' in the web host and DNS host settings
  • If your DNS provider does not allow you to specify server priorities, you need to make sure that mx.todhost.com is the record with lower priority value, to receive emails without any errors.

 

Unable to receive specific emails:

If you are unable to receive specific emails, check whether the email server that sends emails, does not relay to our Mail, or only to your domain account. In some cases, if you have set up local email delivery settings in your previous host, the emails sent from your previous email server will be delivered internally, and will not be delivered to your mail accounts.

When you switch from the previous email service provider, you need to update the Incoming and Outgoing Email server settings for email clients such as Outlook/ Thunderbird/ iPhone/ Android mobile devices, as per the recommended Server names and ports.

 

Unable to receive emails from website contact forms:

When you use 'Contact us' forms or 'Webforms' from a website, the Submit option is typically used to send emails. These emails are triggered from your Website Hosting Provider (Web Host). In most cases, the website's domain name matches the domain name in the email address they are sent from. Ex: www.yourdomain.com/contact.html page will submit the details to contact@yourdomain.com. 

In this case, the Web Host or email server which triggers an email wrongly assumes that the emails should be delivered locally because the domain name is the same. To fix this, open the WebHost settings and choose the Remote Email server option to denote that these emails should be delivered externally. You'll need to check for any Local Email Delivery configuration and switch off the WebHost's local setting. In case you need further support regarding this, contact your respective DNS provider. This will ensure that emails from webforms reach the Mail servers and are delivered to the correct email accounts.

 

Further reading:
 
How to Solve Email Bounce Back Issues
 
How to configure Email Client
 
How to fix error 550 no such user here

 

Troubleshoot MX Record Addition

DNS Provider - Registrar conflict

When you register the domain with one provider, but point the Nameservers to another provider, then the MX Records added in your Domain Registrar is not considered valid. You might have changed the DNS Provider for hosting your website or for your previous email provider configuration or based on your choice.

The MX Records added in the provider where the Nameservers are pointed will only be effective and valid. Hence, do a 'NameServer' Lookup for your domain, to check where your domain is hosted. You may also check with your Domain Registrar or the technical contact for your domain on where the name servers are pointed to if you are not sure.

 

Longer TTL

TTL (Time To Live) is the time specified in your DNS for each change in your DNS to be effective. If you have a huge TTL value (24 hrs/ 48 hrs), then the MX Records might not be provided during the verification process. It might take up to 12 - 24 hours for DNS changes to take effect, based on the TTL set. Please check the TTL value and try verifying after a while.

Incorrect Values

The way the MX needs to be added often varies with different DNS Providers. Hence it is recommended to check the help pages or instruction manuals or reach out to the support team of your DNS provider, to add the respective MX Records.

 

Conclusion

In creating the error ‘550- Unrouteable address’, the sender and the recipient email server address has a vital role. In fixing the error, the first step is to verify whether the email addresses are correct or not. It should be the foremost goal because most of the ‘550-Unrouteable address’ happen due to the wrong email address both in sender and receiver sides. Setting the MX records correctly helps the administrators to rectify the error. Now, most of the email servers maintain strict security measures. So meeting the security or quality standards not only protect your email servers but also help you to communicate with other servers.  It eliminates the chances of displaying the error. You can always opt for any server management company to keep your server error free. In brief, the fixing of the error ‘550- Unrouteable address’ is solely under the control of the server users. Following the required standards and procedures makes the server free from hazards of email communication which is highly important in meeting the enterprise requirements.

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