Telefax server application, does it exist?
 

If so, please guide me to the best ones.

OS does not matter. Well, FreeBSD is prefered, but also MS.

Here's the info:

1. I have, let's say, 100 phonenumbers in my database.
2. I wish to send them all a telefax message, the same to all of them.
3. I wish to do so from my server.

What do I need to solve this?

A fax gateway or an ISDN phone line to your server.

Thanks, I'll look into the fax gateway thing.