No such user ошибка

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 teh cPanle 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.

PostgreSQL 12.2
Red Hat Enterprise Linux Server release 7.9
PgBouncer 1.14

[databases]
* = host=127.0.0.1 port=5432 user=*

[pgbouncer]
logfile = /var/log/pgbouncer/pgbouncer.log
pidfile = /var/run/pgbouncer/pgbouncer.pid
listen_addr = ***.**.***.***
listen_port = 3306
auth_type = hba
auth_hba_file = /data/postgres/pg_hba.conf
admin_users = postgres
stats_users = postgres
pool_mode = session
ignore_startup_parameters = extra_float_digits
max_client_conn = 200
default_pool_size = 50
reserve_pool_size = 25
reserve_pool_timeout = 3
server_lifetime = 5
server_idle_timeout = 120
server_connect_timeout = 5
server_login_retry = 1
query_timeout = 60
query_wait_timeout = 60
client_idle_timeout = 60
client_login_timeout = 60
syslog=1
;;verbose=2

I am trying to set up and test PgBouncer with an already existing PostgreSQL 12 server but there must be something I am missing. I know my pg_hba file is properly set up, but when I try to connect using psql I get a «No such user» error.

psql -h HOST -U USER -p 3306 -d postgres
psql: error: could not connect to server: ERROR:  no such user: USER

From the log file

2021-04-27 09:53:36.112 EDT [6077] LOG kernel file descriptor limit: 1024 (hard: 4096); max_client_conn: 200, max expected fd use: 212
2021-04-27 09:53:36.113 EDT [6077] LOG listening on ********:3306
2021-04-27 09:53:36.113 EDT [6077] LOG listening on unix:/tmp/.s.PGSQL.3306
2021-04-27 09:53:36.114 EDT [6077] LOG process up: PgBouncer 1.14.0, libevent 2.0.21-stable (epoll), adns: evdns2, tls: OpenSSL 1.0.2k-fips  26 Jan 2017
2021-04-27 09:53:38.806 EDT [6077] LOG C-0x559d9430a420: (nodb)/(nouser)@********:34744 registered new auto-database: db=postgres
2021-04-27 09:53:38.806 EDT [6077] LOG C-0x559d9430a420: (nodb)/(nouser)@********:34744 closing because: no such user: ********(age=0s)
2021-04-27 09:53:38.806 EDT [6077] WARNING C-0x559d9430a420: (nodb)/(nouser)@********:34744 pooler error: no such user: ********
2021-04-27 09:53:38.806 EDT [6077] LOG C-0x559d9430a420: (nodb)/(nouser)@********:34744 login failed: db=postgres user=********
2021-04-27 09:54:36.113 EDT [6077] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2021-04-27 09:55:36.113 EDT [6077] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2021-04-27 09:56:36.113 EDT [6077] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2021-04-27 09:57:36.113 EDT [6077] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2021-04-27 09:58:36.113 EDT [6077] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2021-04-27 09:59:36.113 EDT [6077] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2021-04-27 10:00:36.113 EDT [6077] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2021-04-27 10:01:36.113 EDT [6077] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2021-04-27 10:02:18.620 EDT [6077] LOG C-0x559d9430a420: (nodb)/(nouser)@********:34832 closing because: no such user: ********(age=0s)
2021-04-27 10:02:18.621 EDT [6077] WARNING C-0x559d9430a420: (nodb)/(nouser)@********:34832 pooler error: no such user: ********
2021-04-27 10:02:18.621 EDT [6077] LOG C-0x559d9430a420: (nodb)/(nouser)@********:34832 login failed: db=postgres user=********
2021-04-27 10:02:36.113 EDT [6077] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us
2021-04-27 10:03:36.113 EDT [6077] LOG stats: 0 xacts/s, 0 queries/s, in 0 B/s, out 0 B/s, xact 0 us, query 0 us, wait 0 us

I can provide more details if needed.

The error commonly occurs when the sending email is rejected because the destination email username cannot be found or is not accessible by the server. Here are the very likely causes of this error.

    Your IP address is blocked by the recipient’s email hosting server.
    Your email address has been compromised and has been blocked by recipient’s hosting server.
    You are sending an email using an ISP that is different to the one you are currently logged on to.
    The recipient’s email address cannot be found, or does not exist.
    The recipient’s email has been suspended or temporarily disabled.
    Your own domain name is invalid, cannot be found, or has been blocked.
    Your email message is being treated as spoofed, and has been rejected by the recipient’s email hosting server.
    The recipient’s email hosting server tried to verify the sender email address, but was unable.
    The recipient’s hosting server is down, and is unable to receive the email.
    The recipient’s inbox is full, and is unable to receive the email.
    The recipient’s email hosting has an anti-spam firewall, and has labelled your message as spam.
    Your own Internet gateway has a firewall, or filtering feature, that intercepted your own email, regarded it as spam, and blocked it to stop you from accidentally sending out spam or a virus-infected email.
    Your email account has been hacked, has been used to send out tons of spam mail, and so has been blocked by the recipient’s SPF (Sender Policy Framework).

Note: The SMTP 550 Error is often a problem at the recipient’s end, which means this error is usually caused by factors outside your email hosting server. However, there are some recommended steps you will want to take to see how you can address this error.

Troubleshooting to Fix a 550 No Such User Error

As noted earlier, this error is usually an error on the recipient’s end. But there may still be ways you can fix the problem. Here are some possible solutions:

        Double-check the recipient’s email address. «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.
        Confirm with the recipient that you have their correct email address. If you have checked the email address and you are certain you typed it correctly, but you still get an SMTP 550 Error, then perhaps you got the wrong email address from the recipient. It could also be that they have changed the domain name or any other part of the address.
        Check your own email address and message. Make sure that your sender email is typed correctly, and check that your email has content. Some email hosting servers can reject emails that are blank, or have no content.
        Try changing your outgoing mail port to 26 or 465. Some servers block port 25 because spammers often use it to send spam, or spoofed emails.
        Scan your computer for viruses and malware. Technically, email addresses don’t get infected; it’s the computers or the hard drives that do. Install a reliable antivirus program, and scan your computer. After the scan, change your email password, just in case you have been hacked.
        Re-try sending the email after a few minutes, or hours. It is possible that the recipient’s server is just temporarily down and may come back up after a while. If you get the error message again, even after a few hours, contact the recipient and inform them that their hosting may be down.
        Use your ISP’s outgoing mail server. Sometimes, it is your own Internet Service Provider or Internet gateway filtering and blocking your emails. If this is the case, you can try using your ISP’s outgoing mail server.
        Contact your ISP. A good solution may be to ask your Internet Service Provider for assistance. After all, they are the one who know their system best, and may be able to help.
        Change all your passwords. Be sure to use a random mix of letters, numbers, and special characters to make a really strong password. Also change your recovery options, since if hackers have gained access to your account they would probably aware of these options, too. As added protection, make a habit of changing your passwords regularly.

Further reading:

Email Problems: What Should I do?

How to Solve Email Bounce Back Issues

How Did My Email Get Compromised and What Can I Do to Stop It?

Managing the Mail Function in CPanel

What is Email Spoofing?

What is Spamming?

Other Possible Causes of «Error 500, No Such User Here»

    Sender email or receiving email account is over-quota
    Mail file permissions are not readable or are incorrect.
    MX records are incorrect ( pointing to the wrong server ).
    Email does not route correctly ( Remote / Local domains )

Sender or Receiving Email Account is Over-Quota

    Full mailbox. Mailbox storage quotas are set to 250MB by default, but some plans allow you to turn off the limit and set mailbox quotas to «unlimited.» If an email account is at or past its capacity, sending out from it won’t work and you’ll get a «Sender Verify Failed» error. To check on the mailbox quota of an email account follow these steps:
        Log in to your Bluehost control panel.
        Go to the Hosting menu and click Email in the submenu.
        Locate the email address having problems in the list, and click view details button on the right to view detailed information about the email account.
        Look for the mailbox quota. If the account is at or exceeding its quota, increase its limit or delete emails to save space.

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.

MX records are incorrect ( pointing to the wrong server )

If you recently moved your domain to Todhost 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.

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 )

The email routing setting in your Zone Editor determines how outgoing email is handled for a particular domain. There are three possible settings:

    Local Mail Exchanger. Use this setting if the domain’s email is hosted by Bluehost, even if the domain uses third-party name servers.
    Remote Mail Exchanger. Use this setting if the domain’s email is not hosted by Bluehost and your MX records are pointed to a third-party email server.
    Automatically Detect Setting. Use this setting if you aren’t sure. The server will decide if the setting should be Local or Remote based on the MX record. This is usually not recommended.

It’s important for the email routing setting to be accurate for each of your domains to prevent any delivery failure issues. Follow these steps to update your email routing settings:

    In the DNS Zone Editor, choose your domain from the drop-down menu.
    Scroll down to MX (Mail Exchanger).
    Click More to expand the section.
    Choose your setting.
    Click Change to save.

How things go wrong with cPanel Remote Mail Exchanger

In cPanel servers, there is an option called “Email routing” which decides how mail is handled for a domain. By default, new accounts created on the server have mails handled by the same server. But when the domain needs to use another server for mail, the email routing has to be set as “Remote Mail Exchanger”.

Here’s how Email Routing is set for a domain in cPanel servers.

Mail server tries to send mails to another server after checking the Remote Mail Exchanger setting for the domain.

Listed below are the situations where mails fail due to this setting.

1. Remote Mail Exchanger not set

To enable external mail servers for a domain, website owners simply set the custom mail servers (MX) records for the domain.

Unfortunately, that is not enough for mails to show up in the external mail servers.

Mails from website forms or other domains hosted on the same server still fail. This happens as the mail server tries to deliver the mail within the server.

To fix the problem, set the correct email routing as per the MX records of the domain.

Also ensure that the correct values are present in the mail server configuration files like /etc/localdomains and /etc/remote domains as well.

2. Incorrect value for Remote Mail Exchanger

Cpanel maintains two domain lists :

    Domains whose mails are on the same server
    Domains whose mails are on remote servers.

When we change email routing for a domain, cPanel automatically adjusts these lists.

For example, when we set Remote Mail Exchanger for a domain, cPanel removes the domain from the local domains list and automatically adds it to the remote domains list.

But this may not always work due to bad server settings.

And when a customer wants to change their domain’s MX to a different provider, say Google, he will set MX in dns records and change email routing to “Remote Mail Exchanger”. Normally, this is enough for mails to show up at Google.

But if for some reason cPanel fails to remove this domain from the local domains list, the mail server will still try to deliver all mail from other domains on the same server locally. This will result in an email error “Recipient Not Found” as the original recipient exists at Google.

In such cases, for mail to work properly, our do the following :

    Set mail routing to “Remote Mail Exchanger”
    Remove entries for the domain from the list of local domains
    Add the domain to the list of remote domains

Final Words

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 an email 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 server’s end.