Hey guys.

I'm new to the forum and hope you guys can shed some light on this question for me. I hope i post this thread in the correct section. If not please excuse my ignorance.

I am busy setting a test platform at my office to simulate a roll-out i'm planning for a client of mine. It consists of a linux (OpenSuse 11.1) firewall / proxy / SMTP server on the outside of the network and a Microsoft Small Business Server 2008 on the lan. The employees of the company travel frequently and will need to be able to check their email from outside the office as well as use the Linux server as an secure SMTP relay. Although the checking of the email from outside the office is no problem, I'm having trouble getting my head around the SMTP part.

The employees use many different types of connections and i would like them to use the linux server as a secure SMTP relay through which they can send all their email. It needs to be a secure service and therefor i was wondering if it is possible to set up sendmail in such a way to authenticate users against the active directory on the 2008SBS.

Currently there are only around 10 employees in the office, but we are planning to use this server for the entire enterprise (all the branch offices) later (around 40 - 50 users). So the solutions needs to be scalable.

I have read a couple of posts in different forums but none of the replies i came across, supplies very useful information around the actual steps, the way you interface between linux and the AD and the components needed on the linux side to achieve this.

If you guys have any other suggestions regarding a different MTA that will be easier or better, please feel free ...

Another question i have is. Since Small business server has a user limit, we might be looking replacing it at some stage with and enterprise server. Since our mail is held by the ISP in POP3 boxes, we will need to change that over to the a spool account and change the MX records to point directly to firewall. My question is, is it better to you port forwarding on the firewall to direct the email to the Exchange server, or is it better to "receive" the mail on the linux server, wash it through a spam filter and then "pass" it on to the exchange?

I don't want to be spoon fed ... i only need someone that can point me in the correct direction and some links to proper documentation in this regard. Some tips on where to start and a logical chronological order of setup steps will be very helpful.

Can any of you boffs out there help me ?

Thanx for a great forum btw.

Regards.

Greenius