TheHolbi

CSF replacement tested in old Centos 7, AlmaLinux 8.10 and AlmaLinux 9.6
The CSF project is continuing as Open Source project, the website is here: https://docs.configserver.dev/
Github: https://github.com/Aetherinox/csf-firewall
And as it was suggested in article https://www.jaspreet.net/2025/09/06/3180/how-to-fix-csf-firewall-error-oops-unable-to-download-no-host-option-provided/ you have to update the content of
/etc/csf/downloadserver
Comment out (or delete) the old content of the file and set the new line of download server: download.configserver.dev
Restart CSF and from the GUI of CWP update Firewall.
The result will be appear in the screen, and the CFS/LFD will update to the current version: Status: csf: v15.01 (CentOS Web Panel)
Or, you can use the solution suggested by @Starburst above.

The DKIM signature issue was resolved as follow:
There were missing lines from the /etc/postfix/main.cf :
#DKIM milter_default_action = accept milter_protocol = 6 smtpd_milters = inet:localhost:8891 non_smtpd_milters = inet:localhost:8891 and the correct /etc/opendkim.conf was :
AutoRestart Yes AutoRestartRate 10/1h LogWhy Yes Syslog Yes SyslogSuccess Yes Mode sv Canonicalization relaxed/simple ExternalIgnoreList refile:/etc/opendkim/TrustedHosts InternalHosts refile:/etc/opendkim/TrustedHosts KeyTable refile:/etc/opendkim/KeyTable SigningTable refile:/etc/opendkim/SigningTable SignatureAlgorithm rsa-sha256 Socket inet:8891@localhost PidFile /var/run/opendkim/opendkim.pid UMask 022 UserID opendkim:opendkim TemporaryDirectory /var/tmp After completed /etc/postfix/main.cf and restarted services, the DKIM signature was properly inserted to the outgoing emails.