Problem delivering mail from Xampp

[Galdhrim]

Well, I am afraid this post will be long and probably will lack useful info to help me to solve the problem, but I will try to provide any info you ask me to figure how to solve this.

Currently I am working on a project for a course named "business over internet", so I am supposed to setup a portal to sell some product or service, and I am using xampp, since it is not a "real" business, so I dont want real customers signing and trying to buy things. But also, since I am supposed to show this thing working, I will need to be able to access the site from internet. To make things more complex, I have another course about making web sites with visual studio.net, so I had to install IIS too (I am using port 6060 for apache, and 6080 for SSL, and Xampp is working fine).

Since my IP is not static, I am using no-ip to have a "domain". I also set up 2 port redirects (to be able to use ports 6060 and 6080 for xampp).

I installed osCommerce and SMF forum, both apps work fine using ssl, but each time they try to send an email message, there is an error.
I configured IIS smtp to have 192.168.0.1 as its default address (it didnt allow me to use 127.0.0.1), and to recive connections from 127.0.0.1 and 192.168.0.1, and the same addresses to allow retransmision (forward? my windows is in spanish). It doesn't ask autentication.

Then, I edited php.ini to use smtp at 192.168.0.1, port 25, and I could send 1 email from smf (I installed another forum, at localhost:6060, to test if these changes were having any effect), but other emails I tried to send just doesn't arrive, I dont get any error message.
Then I tried to send email using the no-ip domain, and I got errors again, probably the SMTP server identify the request coming from the no-ip domain, or maybe from my external (dinamic) IP... and at that point, I came here and began to write.

What do I need? I need to find a way to send emails, I dont care if I use IIS smtp, or if I have to use Mercury (but I will have to make it work in a free port, since port 25 is already in use), or any trick that can solve this.

I still have some time to make this thing work, since for now I am working on the other part of the project (why the proposed business should work, and all that).

Usually I would be wanting to learn about "the best way" to do these things, but right now, without having had the network courses yet, anything that works is fine to me.

Thanks