550 Please turn on SMTP Authentication in your mail client.

Error Examples:

When someone tries to send you mail from gmail/outlook, they get a reply mail with the following errors:

550 Please turn on SMTP Authentication in your mail client. mail-lf1-f43.google.com []:42770 is not permitted to relay through this server without authentication.
Remote Server returned '550 5.7.368 Remote server returned authentication required to relay -> 550 Please turn on SMTP Authentication in your mail client. ;mail-oln040092255101.outbound.protection.outlook.com;(APC01-HK2-obe.outbound.protection.outlook.com) []:9693 is not;permitted to relay through this server without authentication.'

Error Solution

The error appears for several reasons. I will try to point out the most common ones I have faced for clients.

One, this domain is listed in /etc/remotedomains, while the domain is actually a local domain or shall use a local exchanger. As the domain is set not to use local mail exchange, hence the MTA is bouncing the mail back from receiving. To resolve this problem, you need to go to:

WHM >> DNS Zone Manager >> Search your domain that is having problem >> Manage

Now, click on the ‘Email Routing Configuration’ just beside the ‘Actions’ button as shown in the screenshot.

In the MX, make sure to set your local MX, and then select ‘Local Mail Exchanger’, then save.

If the domain was in remotedomains, and you did the above, and the issue is still not fixed, then you may want to run the following command to rebuild the remotedomains and localdomains file for Cpanel

/scripts/checkalldomainsmxs –yes

The second reason, the issue can appear, if you have defined two different MX and one of them, does not have the user, to whom the mail is trying to deliver. You should try to avoid such ambiguity. If you use multiple different MX, then you need to make sure, both of them accepts the same set of the user list.

Hope this works for you. Let me know the result.

Error: The websocket handshake failed at PM – Cpanel Terminal


When you try to open the terminal from Cpanel, it shows you an error in the red screen like the following:

The WebSocket handshake failed at 1:34:27 PM.


The error is appearing because Cpanel uses a socket to create a terminal window for you from the Cpanel. But this verifies the origin of your URL. If you are behind a proxy, then Cpanel won’t let the socket establish.

Most of the time, I have seen the user using Cloudflare behind the domain and using the same domain to access the Cpanel. Unfortunately, Cloudflare’s proxied IP won’t be able to create the websocket. Hence, you must use a domain or hostname or the server IP to access the Cpanel, to use Terminal.

Cpanel Hosting Tries to Send Mail using Localhost for Remote Relay from PHP Script

Question: When I try to send mail using a PHP script in Cpanel, it automatically switches the SMTP hostname to localhost, even if I use a remote relay like sparkpost or mailgun. How to fix this?


The reason behind the behavior is, by default Cpanel doesn’t let your customers use remote SMTP using PHP. This is controlled using a feature called ‘SMTP Restriction’. Go to WHM, log in using root, from Security Center select “SMTP Restrictions” and now, disable this. Your script shall now be able to send mail using remote SMTP like sparkpost/mailgun/pepipost.

Apache detected an error in the Rewrite config. httpd_ls_bak: Syntax error in -C/-c directive: Include/IncludeOptional: Could not open directory /usr/local/apache/conf.modules.d: No such file or directory Please try again. – Cpanel Error

You might see the following set of errors with Cpanel

When trying to remove the redirect from Cpanel

Apache detected an error in the Rewrite config. <pre>httpd_ls_bak: Syntax error in -C/-c directive: Include/IncludeOptional: Could not open directory /usr/local/apache/conf.modules.d: No such file or directory </pre> Please try again.

/scripts/rebuildhttpdconf generates an error like the following:

httpd: Syntax error in -C/-c directive: Include/IncludeOptional: Could not open directory /usr/local/apache/conf.modules.d: No such file or directory


Previously, we reinstalled apache24 to solve the issue like the following:

yum reinstall ea-apache24

Although you may also reinstall the apache config runtime extension, that shall fix the issue as well.

rpm -e --nodeps --justdb ea-apache24-config-runtime.noarch
yum install ea-apache24-config-runtime.noarch

Now you may rebuild the httpd conf or remove the redirect from cpanel without any problem.

failed to open db file /var/spool/exim/db/ratelimit: permission denied

Cpanel incoming mails are failing, with an error in the exim_mainlog as following:

failed to open db file /var/spool/exim/db/ratelimit: permission denied

The error is appearing due to some permission issues with the exim db or the files are corrupted. These files recreate when the exim restart. Hence, we can do the following:

# delete the db files
rm -rf /var/spool/exim/db/*

# restart exim
service exim restart

# fix permission of exim spool
chown -Rf mailnull.mail /var/spool/exim
chmod 0750 /var/spool/exim

You should be done now.

How to run composer with different PHP versions in Cpanel?


When we try to run a composer command, like update, we usually do the following:

composer update

Cpanel has multiple PHP binaries, but in this case, we are unable to select a specific PHP binary to use, instead we have to run it with the default one, how to run composer update with a different php binary in cpanel?


composer binary file, is a phar file. PHAR is necessarily a PHP Archive and usually automatically detect the running php. But as it is essentially written in php, you may explicitly run it with a different php binary, if you want. To run composer with different php binary, first, you need to find the location of composer. You may do so, using the following:

root@mirage [~]# which composer

Cpanel different php binaries are available under the following kind of directory:


XX is the version number of PHP. So for example if you need to use PHP 7.4, you would need to run using the following:


Now, to run composer update along with PHP 7.4 binary, you may do something like the following:

/opt/cpanel/ea-php74/usr/bin/php /opt/cpanel/composer/bin/composer update

First, make sure you are in the directory where you want to install laravel, for example, something like the following:

cd /home/username/public_html

Then, you may run the above command:

/opt/cpanel/ea-php74/usr/bin/php /opt/cpanel/composer/bin/composer update
or in case, you want to to install
/opt/cpanel/ea-php74/usr/bin/php /opt/cpanel/composer/bin/composer install
or may be, you wan to run update with no-scripts
/opt/cpanel/ea-php74/usr/bin/php /opt/cpanel/composer/bin/composer update --no-scripts

Uncaught ErrorException: require(/home/username/public_html/vendor/composer/../../app/Helpers/helper.php): failed to open stream: No such file or directory in /home/username/public_html/vendor/composer/autoload_real.php:71

Error Details

While trying to run any of the following with Laravel composer installer, you see an error similar to the following:

Uncaught ErrorException: require(/home/username/public_html/vendor/composer/../../app/Helpers/helper.php): failed to open stream: No such file or directory in /home/username/public_html/vendor/composer/autoload_real.php:71

How to fix this?


The error is appearing, most likely you forgot to add the ‘app’ directory of laravel in your root directory. Make sure, you have the ‘app’ directory in your root directory, then run any of the following:

If this is the first time, you need all laravel packages, run:

composer install

If this is not the first time, you may run the following:

composer update

Good luck.

How to Uninstall Let’s Encrypt from Cpanel / WHM

To uninstall the Cpanel / WHM plugin for Let’s Encrypt, login to your SSH for root and run the following:


It might take sometime, once completed, it should remove let’s encrypt as a provider from your AutoSSL plugin.

How to Install Let’s Encrypt in Cpanel

Let’s Encrypt is a popular tool to use free SSL for your website. Cpanel comes with Sectigo free ssl service through requesting and pooling system. Although, you might feel interested in getting the SSL released immediately without a queue based approach, and would prefer to use Let’s Encrypt that’s why.

There are two ways, you may install Let’s Encrypt in Cpanel.

  1. Using Cpanel Plugin

First one would be using the plugin created by Cpanel. Login to your server as root:

ssh root@server_ip

Then, run the following to install Let’s Encrypt in your cpanel system


It might take a couple of minutes, then it should install Let’s Encrypt as a provider in AutoSSL.

Now, go to WHM >> Manage AutoSSL and select Let’s Encrypt as the provider instead of Sectigo Cpanel default. You need to check the Agreement rules under the Let’s Encrypt selection and you may create the account in Let’s Encrypt using the same tool.

Once done, your new SSLs would be issued using the Let’s Encrypt tool through Cpanel AutoSSL plugin.

2. Using FleetSSL

There is a 3rd party tool, existed before Cpanel provided a plugin for Let’s Encrypt. It’s FleetSSL. One key benefit of using FleetSSL is that, it allows the Cpanel end users to control issuing and renewing the SSL from Cpanel. One key cons of using FleetSSL is that, it is not free of charge, it comes with 30$ one time fees. But mainly hosting provider would not mind to use this as it is a nice addition for the end user feature set in a hosting provider’s point of view.

You may check for details here:


Now, once you complete installing Let’s Encrypt SSL, you may now use Let’s Encrypt for different cpanel services like webmail/cpanel/whm/calenders/MTA services. You may check the following to know how to:

[ERROR] Can’t open and lock privilege tables: Table ‘mysql.servers’ doesn’t exist in engine – Resolution

There are times, you may see the following error in your MySQL/MariaDB based Cpanel server:

[ERROR] Can't open and lock privilege tables: Table 'mysql.servers' doesn't exist in engine

The issue is most likely related to your Innodb tablespace got corrupted, and hence some tables under the mysql database got locked out as some of them use Innodb storage engine. One of the outcome of the symptom is, if you try to add a user to a database, it doesn’t add or show the green notification any longer in cpanel mysql databases section. Instead it just stops.

The only and best way to properly fix this would be restore the ‘mysql’ database or just the ‘servers’ table from your backup. If you don’t have one, you may just create the ‘servers’ table using the following SQL statement:

CREATE TABLE `servers` (
`Server_name` char(64) NOT NULL,
`Host` char(64) NOT NULL,
`Db` char(64) NOT NULL,
`Username` char(64) NOT NULL,
`Password` char(64) NOT NULL,
`Port` int(4) DEFAULT NULL,
`Socket` char(64) DEFAULT NULL,
`Wrapper` char(64) NOT NULL,
`Owner` char(64) NOT NULL,
PRIMARY KEY (`Server_name`)

You may require to drop the table first. Now, if you can’t do this either, then there is only one way left, is to uninstall your MariaDB installation, and let Cpanel/WHM to install them for you.

Get a Backup First:

cp -Rf /var/lib/mysql/mysql /root/
rm -Rf /var/lib/mysql/mysql

Uninstall MariaDB:

yum remove MariaDB*

Now, you may install the latest MariaDB from WHM >> MariaDB/MySQL Upgrade and proceed accordingly. This should install the latest for you with a fresh ‘mysql’ database for you. But it will not alter your other data files, means your other databases should be fine.

One thing, you need to remember, after a fresh mysql installation with the old data files, you will have the authorizations missing. You would have to recreate the database users manually to get the privileged table filled up.