From time to time, Squirrelmail gives this error on a Plesk machine:
Error opening /var/lib/squirrelmail/prefs/default_pref
Could not create initial preference file!
/var/lib/squirrelmail/prefs/ should be writable by user apache
Please contact your system administrator and report this error.
Squirrelmail depends on safe_mode being off. Let’s see if this is the case:
# grep ^safe_mode /etc/php.ini
safe_mode = On
Since this is a multi-domain system, we want to make changes only to the effected subdomain, in this case the webmail.* subdomain. But changing the Plesk config won’t help, since Plesk will just overwrite it. So we create a second file, that will load after, and thus override the Plesk file:
# vi /etc/httpd/conf.d/zz011_squirrelmail_safemode_fix.conf
And add the following:
<Directory “/usr/share/squirrelmail”>
php_admin_flag safe_mode off
</Directory>
Now check your apache config and restart gracefully:
# httpd -t
OK
# apachectl graceful
Reload Squirrelmail in your browser – it should work now
