Firewall and SMTP

May 17, 2007 1 Replies

I need to secure my network. I would like to prevent SMTP from leaving my network unless it comes from one specified server( email server). This should prevent my network from becoming a zombie of spams. How to I go about this? Will protocol binding do ? How do I test if it works?


thanks



OK, that is normally a pretty easy task.

create the following ruleset for your packet filter (whatever device that is):

from to service/port protocol action

------------------------------------------------------------------- email_server any smtp 25 tcp allow LAN any smtp 25 tcp log + deny

Packet filtering will do.

try connecting to external SMTP Servers from the workstation, look what happens and watch the logfile.

Wolfgang

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required