Lỗi this is an informative message sent by năm 2024

One common error you can get when sending email is the “550 No Such User here” error. This error occurs when the sending email is rejected because the username cannot be found or is not accessible by the server. There are several reasons why you would get a “550 No Such User Here” error.

  • Mail file permissions are not readable or are incorrect.
  • The email address was typed incorrectly.
  • MX records are incorrect ( pointing to the wrong server ).
  • Email does not route correctly ( Remote / Local domains ).

This error can go both ways, meaning, people sending to your server may get the error and when you send from your server to another you may get the error. Depending on where the error bounce is generated from will determine what you can do about fixing the error.

If you get “550 No Such User Here” bounces sending from your server to another server, you most likely will need to contact the host or email administrator of the server you are emailing to fix it.

If you are getting complaints that people sending to your server are getting this bounce, you can check / change the settings on your servers end. Below are the reasons why the 550 error may occur when you email.

Mail file permissions are not readable or are incorrect

All our servers store email in the “mail” directory of the “home” folder of your cPanel account. If the file permissions are corrupted ( sometimes caused by server moves, back up restorations, or recently uploaded files through FTP, etc.) you will get this error for all your emails. This is a simple fix. You can contact tech support to have the file permissions fixed on your server. On VPS and Dedicated servers, you can run the following from command line:

[root@vps#### ~]$ fixperms userna5

This will reset all your file and folder permissions to folders 755 and files 644 for the cPanel user userna5. If the email bounce is coming to you when you send to another server and it’s permissions related, the person you are emailing will need to contact their hosting provider to fix the permissions on their end.

The email address was typed incorrectly

“550 No Such User Here” Errors can occur when the email address you are sending to is typed incorrectly. In this case, just make sure you have the email address spelled correctly.

MX records are incorrect ( pointing to the wrong server )

If you recently moved your domain to InMotion Hosting and you started receiving these errors, you may have a DNS nameserver or MX record problem. The MX records point your email address to a specific server. If the MX record is pointing your domain to the old hosting company and you removed all your email accounts off that server, when you go to send your email, you will get the “550 No Such User Here” error. You will want to check the following through command line:

[root@vps#### ~]$$ dig example.com mx ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.10.rc1.el6_3.6 <<>> example.com mx ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8149 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 3 ;; QUESTION SECTION: ;example.com. IN MX ;; ANSWER SECTION: example.com. 14400 IN MX 0 example.com. ;; AUTHORITY SECTION: example.com. 54747 IN NS ns2.inmotionhosting.com. example.com. 54747 IN NS ns1.inmotionhosting.com. ;; ADDITIONAL SECTION: example.com. 13322 IN A 66.117.4.177 ns1.inmotionhosting.com. 11994 IN A 74.124.210.242 ns2.inmotionhosting.com. 11994 IN A 70.39.150.2

The example above shows that domain example.com points to the ns1.inmotionhosting.com and ns2.inmotionhosting.com nameservers and that the MX routes to the InMotion Hosting server.

Make sure your nameservers are pointing to us. If your nameservers do not point to our server, then your domain will not route to our server unless you make special DNS changes at the host the nameservers point to.

Make sure the MX records for your domain are sending to the correct server. If your domain does point to the correct server, check the MX records to see if the email is pointing to the correct server in the cPanel MX entry.

If your nameservers and DNS are correct, then you will need to check the email routing. If the bounce message is from you sending to another server, then the person receiving the email will need to check with their email provider for a resolution.

Email does not route correctly ( Remote / Local domains )

In the case that you are receiving bounces to a specific email address, you will need to find the MX records and the nameservers for the receiving domains DNS. Run the following DIG in the Linux command line to find the Receiving servers nameservers.

To find out if your domain is on the receiving email servers DNS nameserver, you can DIG the domain for their nameservers. Once you get the nameservers for the receiving domain, you can check the DNS for your domain using their nameservers. Below will explain in detail.

Dig the receiving server domain to find the nameservers:

Below shows what a DNS MX record DIG looks like for notexample.com.

[root@vps#### ~]$ dig notexample.com mx ; <<>> DIG 9.8.2rc1-RedHat-9.8.2-0.10.rc1.el6_3.6 <<>> notexample.com ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8587 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2 ;; QUESTION SECTION: ;notexample.com. IN A ;; ANSWER SECTION: notexample.com. 14400 IN MX 0 notexample.com. ;; AUTHORITY SECTION: notexample.com. 85619 IN NS ns1.somenameserver.com. notexample.com. 85619 IN NS ns2.somenameserver.com. ;; ADDITIONAL SECTION: notexample.com. 13322 IN A 25.22.80.62 ns2.somenameserver.com. 18391 IN A 25.22.80.62 ns1.somenameserver.com. 18391 IN A 25.22.67.43 ;; Query time: 1 msec ;; SERVER: 74.124.198.200

53(74.124.198.200) ;; WHEN: Thu Mar 7 06:08:06 2013 ;; MSG SIZE rcvd: 136

The results of this DIG shows that the nameservers for the receiving server notexample.com has the nameservers of ns1.somenameserver.com and ns2.somenameserver.com. The MX record points to notexample.com which has an IP that points to the server the nameservers are on. Next you can check your domain in the receiving server nameservers.

Checking if your domain is in another servers DNS:

Now that you have the receiving server nameservers for the notexample.com domain, you can DIG the DNS records at the receiving servers end to see if your domain is in their DNS nameserver. The following is an example of the DIG command in shell that will look up example.com on the notexample.com server.

dig @ns1.somenameserver.org example.com ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.10.rc1.el6_3.6 <<>> @ns1.somenameserver.org example.com ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 11023 ;; flags: qr aa rd; QUERY: 1, ANSWER: 1, AUTHORITY: 2, ADDITIONAL: 2 ;; WARNING: recursion requested but not available ;; QUESTION SECTION: ;example.com. IN A ;; ANSWER SECTION: example.com. 14400 IN A 70.39.251.58 ;; AUTHORITY SECTION: example.com. 86400 IN NS ns2.somenameserver.org. example.com. 86400 IN NS ns1.somenameserver.org. ;; ADDITIONAL SECTION: ns1.somenameserver.org. 14400 IN A 70.39.251.58 ns2.somenameserver.org. 14400 IN A 70.39.251.58 ;; Query time: 66 msec ;; SERVER: 70.39.251.58

53(70.39.251.58) ;; WHEN: Fri Mar 8 06:16:18 2013 ;; MSG SIZE rcvd: 140

The previous response shows that example.com is in the DNS on the notexample.com server. This means that the emails sent to notexample.com are seeing example.com in their DNS, looking for the email address on the notexample.com server, and rejecting it because there is no email address on the server.

To fix this, you will need to contact the hosting company or the domain owner that you are sending to, telling them that your emails cannot go through to their server because your domain is in their DNS. They will ned to “Kill the DNS“, change the routing to remote on the receiving server, or remove your domain from their DNS nameserver.

If your domain is not in their DNS nameserver:

If example.com was NOT found in the nameserver on the receiving server you will get the following not found response.

dig @ns1.inmotionhosting.com google.com ; <<>> DiG 9.8.2rc1-RedHat-9.8.2-0.10.rc1.el6_3.6 <<>> @ns1.inmotionhosting.com google.com ; (1 server found) ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 63529 ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 0 ;; QUESTION SECTION: ;google.com. IN A ;; Query time: 0 msec ;; SERVER: 74.124.210.242

53(74.124.210.242) ;; WHEN: Fri Mar 8 06:20:03 2013 ;; MSG SIZE rcvd: 28

In this case, you can try checking your email routing. If you are sending from your server with us, you will need to set the email routing to local in your MX entry of your cPanel. If you are using a 3rd party application like Google APPs, you will need the routing set to remote.

If this does not fix the problem, then you will want to contact tech support to find out if there is a routing issue with your DNS.