Postfix receive email but not send email


I worked till 2005,6 with virtualmin, webmin usermin and sendmail and hat never a problem. Since a few days i have a new vps and webmin, usermin, but now is virtualmin installing postfix. Receive emails is working, but i can not send emails also not when i try to do it with usermin. My mac is telling the smtp server not relay. Have in between al 5 x installed everything new, after different changes please can you tell me what is wrong.?

With Kindly Regards

Arjan van Dam

This appears to be a duplicate of this post here:

?? what do you mean

eh wtf is going on here andreychek?

Two identical posts came through at the same time, but I appear to have linked to the wrong one… try this one here instead: