How to change PHP version for webmail in Plesk for Linux?

Question

How to change the PHP version for webmail in Plesk for Linux?

Answer

Note: Roundcube webmail now uses PHP 8.3 in Plesk on all supported OSes except RHEL 7, CentOS 7, CloudLinux 7 and Ubuntu 18.04.

Note: Horde webmail does not provide support for PHP 8.0 and later versions due to external limitations. It uses the latest supported PHP version - 7.4. For security reasons, we recommend to switch to Roundcube webmail instead.

1. Connect to your Plesk server via SSH.

2. Create a directory for custom configuration templates:

   # mkdir -p /usr/local/psa/admin/conf/templates/custom/webmail

3. Copy original file roundcube.php to the created directory:

   # cp /usr/local/psa/admin/conf/templates/default/webmail/roundcube.php /usr/local/psa/admin/conf/templates/custom/webmail/

4. Run the command below to list all available PHP versions. If a required PHP version is not listed, install it using the steps from this KB article.

   # plesk bin php_handler --list | grep fastcgi

   id: display name:
   plesk-php83-fastcgi    8.3.16
   plesk-php84-fastcgi    8.4.3

5. Modify the configuration file of Roundcube:

   5.1. Open the roundcube.php file in a text editor. In this example, we are using the vi editor:

   # vi /usr/local/psa/admin/conf/templates/custom/webmail/roundcube.php

   5.2. Change the PHP handler to any other id from step 4. In this example, we are setting PHP version 8.4:

   • Before

     FcgidInitialEnv PP_CUSTOM_PHP_CGI_INDEX "<?php echo $roundcubePhpHandler; ?>"

   • After

     FcgidInitialEnv PP_CUSTOM_PHP_CGI_INDEX plesk-php84-fastcgi

   5.3. Save the changes and close the file.

6. Regenerate configuration files to apply the changes:

   # plesk repair web -server -y