How to fix email error – User unknown in local recipient table

Emails now a ubiquitous part of everyday life, whether you are at work or at home, most chances that you are using emails every day. Sometimes we face the emails error issues, where emails bounce back with some sort of errors.

Today we will try to solve the email error issue such as User unknown in local recipient table. In this article, we will see how to fix this issue, why people face such issue and what is a local recipient table error or in other words User unknown in local recipient table

Bounce Back Error Message

Mail server like Postfix, MailEnabler, etc commonly reported an error such as User unknown in local recipient table. This bounce-back error message is shown below:

MailEnable: Message could not be delivered to some recipients.
The following recipient(s) could not be reached [SMTP:Cyber@mailserver.com]:
Remote SMTP Server Returned: 550 5.1.1 : Recipient address rejected: User unknown in local recipient table

This bounce message shows that the mail server can’t find the email address cyber@mailserver.com and mail server reject the mail and bounce back the email error with User unknown in local recipient table to the sender.

For any email to be delivered at its location, the mail server needs to know the delivery path of the mail. There are two locations the emails are delivered, local email box within the server and remote email box outside the server. Sometimes, mail servers get messed up with mail delivery path and try to find out the mailbox for local email address outside of the server.

Happens due to some reasons:

  • Misconfigurations of DNS Records
  • Bad Email Routing
  • Bad Email Server Setup
  • Email not entirely existing on the recipient error(Given the wrong email by mistake)

Misconfigurations of DNS Records

To send an email, mail server always looks up for mail record (MX) of the domain in the DNS record. Where mail server decides whether an email will deliver locally in the server or deliver remotely outside the server. So your MX record should be configured correctly, to deliver the email to the right path of the domain.

Mail record (MX) issue occur usually when you:

  • Move from one host server to another host server and your DNS record have not been updated to a new server.
  • Change DNS records were not updated yet (In this case you can just wait for DNS records to get updated)

Bad Mail Server setup – Issue #01

Mail server also provides an option to set the email path of the domain using Email routing. You can set it as a local or remote server. Mails sent outside the server when it is set as remotely. But there some configuration errors occur when you set it up.

Let’s take an example here, If your domain uses Google server as an MX record but in email routing, you set it as a local to delivers emails locally. Consequently, there is no email box is set locally within the server, therefore it will through an error User unknown in local recipient table. If you want your emails to deliver successfully without an error you have to set email routing to a remote server for your remote email box.

You can also take a look at other similar error on How To Fix 550 Permanent Failure For One Or More Recipients

Bad Mail Server setup – Issue #02

Additionally, the wrong mail server setup also can cause the User unknown email error.

In mail servers like Postfix, the decision to deliver mails within the server depends on a setting called mydestination

A sample setting in postfix server config file looks like:

mydestination = $mydomain, localhost.$mydomain, localhost

Here, any mails sent to the domains added in mydestination setting are to be delivered within the server. At times, we see that the domain associated with the server name is wrongly added in mydestination setting. On a server srv1.xyz.com, when xyz.com is added to mydestination setting, mail server tries to deliver mails for cyber@xyz.com within the server.

And when there is no exact mail address created on the server, mail bounces with error User unknown in local recipient table.

Now let us see how we can solve this error and send emails to the correct mailbox.

How to fix User unknown in local recipient table error?

To fix the email error User unknown in local recipient table, corrects the domain configuration on the server which includes:

  • Remove wrong entries from Domain’s DNS
  • Correct Mail path for the domain depending on the MX records of the domain
  • Also, make sure you provide the right email from recipient

At times, even when the domain entries are correct, this error still remains. This shows that the problem lies with mail server configuration.

To solve the error in mail servers like Postfix, we adjust the mail server configuration entries like mydestination to ensure that server handle mails only for intended domains. In case of MailEnable server, we configure utilities such as MERoute which can force any mail to a remote server. Thus after making these changes, a mail is correctly routed to its mailbox.

User Unknown in Table

You can also guess by the title of this error, that your entered email account does not even exist in the recipient server, which means either they forgot to add their email account to server, or they provided you a wrong email. It is also possible that your recipient has moved to a new server, in which case it is on their end to fix the issue. You can let them know by any offline means or another medium to correct the issue or create an email account in their server.

Conclusion

As you can see there are no hard or fast rules as to what could cause this issue, there are various reasons due to which this issue can arise. But depending on our discussion above you can match your issue with the required problem and then try to go along the solution route. However mostly this issue is on the recipient end, it is better to contact them too and let them know about the situation. In a general sense you can achieve 10/10 email score using this guide.