I need to make an SMTP proxy. And I would like collect the communities thoughts on this.

Have you done this? If so:
*What Linux flavor did you use?
*What application?
*Is there a how to?

If you have not done this but have an idea on it, or know where to find a how to guide? Then please share.

I will be using SLES for the build.
This will more than likely look like:
Mail_server==>SMTP_proxy==>Firewall==>Internet==>Domain_mail_server

Well I am off to hit the

Thanks.

Can we back up and ask what you actually want to achieve in the first place? It doesn't sound like you actually want an SMTP proxy to me, but a mail gateway. SMTP proxies exist, e.g. nginx, but they really are about actually proxying the individual SMTP protocol requests and such, whereas a mail gateway would accept all outbound mail in it's own right, and then forward on, at an entire email level, the data to the destination. The latter is *much* more common, and any popular MTA, eg. postfix, qmail, sendmail will do that just fine.

Chris, thanks for the input. This is a great help. You are right it does sound like a mail gateway is what I need.

I have been reading up on postfix and thus far it seems that it could provide the service I need. Though I think iptables could do the same?


email==> app/email server (port destination 7060) ==>mail gateway (port 7060 inbound; outbound port 25) ==> firewall ==>Domain mail server (i.e. phone#@txt.att.net)

iptables? No certainly not.