Sending Mail Error

The server is preventing unauthenticated users from sending mail through it; your server's doing what it's supposed to do.

The "fix" is exactly what's needed: users are required to authenticate prior to sending email. Have clients set their Outlook or other email client to use the same settings as the incoming server. That should fix it.

Although the server returns the error, it's actually a client configuration error.

 

I'm having this problem as well, but I'm using a vbulletin webmail hack. The hack itself works fine, buts the smtp authentication is messing up

Connection to mydomain.com:25....
Rcvd: 220-server.host.com ESMTP Exim 4.63 #1 Thu, 15 Feb 2007 08:30:58 -0600
Rcvd: 220-We do not authorize the use of this system to transport unsolicited,
Rcvd: 220 and/or bulk e-mail.
Sent: helo localhost
Rcvd: 250 server.host.com Hello localhost [xxx.xxx.66.3]
Sent: MAIL FROM:Forums
Rcvd: 501 Forums: missing or malformed local part (expected word or "<")
Sent: RCPT TO:user@recipient.com
Rcvd: 503 sender not yet given
Sent: DATA
Rcvd: 503 valid RCPT command must precede DATA
Sent: QUIT
Rcvd: 221 server.host.com closing connection
Rcvd:


I setup pop/smtp as mydomain.com 110 for pop3, 25 for smtp and user@mydomain.com and password for login. For smtp auth type, I have "none", also tried "login".