- SMTP ports got blocked after enabling Plesk Firewall
- CSF (Config Server Firewall) is installed on the server
# csf -v
csf: v11.00 (generic)
CSF conflicts with Plesk Firewall.
There is no reason to use two similar firewall solution simultaneously. CSF, in general, have the same feature set as Plesk firewall with fail2ban.
In order to uninstall Config Server Firewall from the server, perform the following:
Log in to Plesk Server using SSH.
Remove CSF from the server:
# sh /etc/csf/uninstall.sh