how to secure smtp/sendmail?

[bstone]

Tomorrow I get to go to a FC2 box which is running smtp/sendmail. I don't know much about it at all, but I know I am being paid some good money to "audit it's security". My plan:

back up existing smtp/sendmail files (where are they located)?
configure yum with more mirrors and run it (is there something i should beware of?)
check logs for any outside connections

for the rest, I turn to the kind people who read these forums....

thank you!

[ewdi]

Use SMTP Authentication module, or else anyone can use it as a relay mail server which worse come to worse spammer would use it to send out spam an dyour server will be the one be blamed for sending spam

[bstone]

Use SMTP Authentication module, or else anyone can use it as a relay mail server which worse come to worse spammer would use it to send out spam an dyour server will be the one be blamed for sending spam

Oh good idea! But, um, I don't know where to get it, what to do, how to fit it in, how to configure it and how not to break everything in the process. Might you know of a how-to?

[ewdi]

can you tell me your config first, like what version is your sendmail, what smtp are you using and etc?

[bstone]

can you tell me your config first, like what version is your sendmail, what smtp are you using and etc?

These are all things I will find out tomorrow when I get there. So:

1) How do I know what version of sendmail it is running?
2) Where are the config filed?
3) Is yum enough to update the packages?
4) Any suggestions in how I might avoid any total meltdowns?

[ewdi]

Here is one How to

http://www.simpaticus.com/linux/howto/html-single/Sendmail-SMTP-AUTH-HOWTO.html

Remember, read it slowly and carefully, it should work :)