WordPress MU

I had a huge problem where users were not receiving email notification with their activation links and so on, and tried everything on the board here that I could find.

My simple solution turned out to be opening up /wp-includes/wpmu-functions.php and replacing all instances of 'wp-mail(' with 'mail('

Let me know if this helps you too.

Thanks for this post. Can you please tell me how to activate smtp authentication on wpmu?
Thanks in advance.

When a user registers the email notification is not sent. The rror on the apache log is as follows:

SMTP server response: 503 This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the domain or address is defined for this server. in C:\\Program Files\\Apache Software Foundation\\Apache2.2\\htdocs\\wp-includes\\wpmu-functions.php on line 1061, referer: http://blog.gorecroot.com/wp-signup.php

I answered this in your other thread. There's a smtp plugin that should work for you. I can't open up more than one window here but if you search the forums, you should be able to find it.

I had the same issue, I don't really know what I am doing but I opened wp-includes --> wpmu-functions.php and I changed all of the instances of "support@" to the email I used for the administrator which is "admin@" and now the signup emails work fine. I get my first confirmation email and then my password email.

EDIT*

I spoke too soon, just tried again and I get the same issue:
activation email sent, activation link says "access denied" first time I click, works second time but does not send password.