I wonder if it's possible to make a free email service on my RaQ. Not necessarily POP3, but redirecting is fine by me.

Does this need expensive software, or are there any scripts made for this? I only need it for 1 domain.

Regards,
Adriaan

There are a number of threads covering this topic. If you do a search for 'free email' or similar you should get the information you are looking for.
Basically, to give a short answer to your question, there are two options open to you:
1. Outsourcing: Use a service such as bigmailbox
2. Inhouse: Install some kind of script to do. There are quite a few available, though the features and costs vary considerably. If you do a search on HotScripts (http://www.hotscripts.com) you should get an idea of what's available.
Shop around a bit and have a good look through these boards and others before you commit yourself or spend any money. Just because you're paying for a script doesn't necessarily mean that it is going to be as good or better than a free alternative (Linux is a lot better than Windows - it's free!)

I've looked at other posts on this forum and searched for scripts on HotScrips.com.

I only found expensive scripts or whatsoever. Isn't there something to just forward email? So users can sign up for only forwarding the mail. I don't need a web based email service.

Adriaan