Symptoms
Horde mailbox export fails with an error message similar to the following error: (Replace $USER with the username/account that owns the email)
tail -f /home/$USER/logs/.php.error.log
[...............]
[03-Mar-2022 16:41:53 America/Sao_Paulo] PHP Fatal error: Allowed memory size of 536870912 bytes exhausted (tried to allocate 198851159 bytes) in Unknown on line 0
Description
This issue usually has to do with php-fpm memory limit for that account and can be resolved by simply increasing the memory_limit value.
Workaround
Open below file and increase the memory_limit to 1 GB: (Replace $USER with the username/account that owns the email)
grep -Ei memory_limit /var/cpanel/php-fpm.d/$USER.conf
php_value[memory_limit] = "1G"
Restart the service:
/scripts/restartsrv_cpanel_php_fpm