I'd like to prevent users from using POP3/IMAP other than via SSL. To do that I am attempting to use the firewall to close non-SSL POP3/IMAP ports.
I am having trouble getting the firewall function to work properly.
: ISPConfig 2.2.40 running on Ubuntu 10.04.4 LTS configured as described in the Perfect Server Manual
I activated all services under Management > Server > Services
, including Firewall
which was initially OFF. On the Firewall
tab I set the following configuration:
Name Port Type Active
FTP 21 tcp no
SSH 22 tcp yes
SMTP 25 tcp yes
DNS 53 tcp no
DNS 53 udp no
WWW 80 tcp yes
ISPConfig 81 tcp yes
POP3 110 tcp no
IMAP2 143 tcp no
SSL (www) 443 tcp yes
Webmin 10000 tcp no
IMAPS 993 tcp no
However, when performing a port scan I am seeing 53, 110, 143 open.
I have not seen any error messages.
I am avoiding configuring a firewall separately because I do not want to interfere with ISPConfig.
Does anyone have any hints?
Is there another way to ensure that users can only use SSL to connect to email services?