I've got a bit of a problem. I have a runing postfix mta(I can access via ssh or webmin) and it works great. But when I tryed sending an email form an email client and set the seting to "don't need authentication for sendng emails"(no authentication when connecting) and the email was sent and recived by a local user it was sent to(that's all ok), but I would like to set up postfix so that it requires authemtication when sending email via SMTP.

How do I do that?

Thanks for all the help