Google apps email

It's not entirely clear to me what you are trying to do. Would you like your Linode to be able to send mail, but not receive it? In that case, you can install a mail transfer agent (MTA) such as Postfix and configure it (main.cf) so that it only sends mail:

inet_interfaces = loopback-only
myorigin = $mydomain
mydestination =

If you want your Linode to funnel all outgoing mail through Google Apps, that's slightly different.

Hi Vance,

Thank you for your reply.

I would only like to send mail from my domain, and only mail that originates at my domain, specifically from a discussion forum. I had mail set up without problems for years. However, I my server was hacked last year and was used to send out spam by the ton until I took it off line. I don't want that to ever happen again.

I will give your suggestion a try and see if I am able to secure the source of the outgoing email.

v/r

Jeff

Ah, OK. I think the configuration I described will do what you want.

Note that any mail which originates locally will be sent, such as from web forms. So it is important to make sure those can't be used to spam people. There are a variety of ways to prevent that, such as restricting the destination e-mail address, adding a CAPTCHA, and rate-limiting form submission. Many well-written web applications already build in some protection; if your forum is one of the popular ones it probably is OK.

Of course, if someone gets shell access to the machine all bets are off. The basic security guidelines in the Linode docs are pretty good.

Good luck!