Issues with Outlook 2003, 2008, 2008

[DemonLee]

We have a Windows Server running PLESK 11 and MailEnable 6, however it does not matter what we do, we cannot send mail to a non local address, it always returns a 503 Error saying it needs 'authentication'.

Before anyone replies asking if Outlook is configured correctly on the Desktops, I am an MCSE and specialise in Building Servers and Secure Mail. There is nothing wrong with MailEnable, we can ping and telnet into the post office and mail boxes. It will send mail to a local address but not a non local address.

 

[IgorG]

What sort of error messages do you have exactly? Any error logs?

 

[DemonLee]

Error Messages

What sort of error messages do you have exactly? Any error logs?

Igor, I gave the error message that we get from Outlook 2003/2008/2010

When a user attempts to use an e-mail address created for the domain within Plesk, we set up the E-Mail Client, normally Outlook 2003/200/2010 but we get the same error 503

'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.'

We can ping the mailserver, we can telnet into it, we can send and receive local mail, but always get that error when sending non local mail. In Outlook we have checked every possible configuration and the fact this is happening on various domains on the same server whilst different clients in different locations are using variations of Outlook, to us this is a server problem but I'll be damned if I can find it..!

Demon

 

[IgorG]

'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.'

The above error means that localhost is not allowed to relay over SMTP to send mail to non-local mail names. Try to allow Relay for localhost in MailEnable SMTP configuration.

 

[DemonLee]

The above error means that localhost is not allowed to relay over SMTP to send mail to non-local mail names. Try to allow Relay for localhost in MailEnable SMTP configuration.

Igor, we already have local relaying open for local host (127.0.0.1/32) and turning on 'relaying' generally is going to open the MailServer to spammers, I am not prepared to do that for obvious reasons.

I have the same settings on my Servers named DS7995 & DS9150

DS7995 does not give this error whilst DS9150 does - the only difference between the two servers is DS7995 has 4GB less RAM and runs Plesk 9.5.2 & MailEnable Standard 7.04 (That Plesk states will not work with 9.5.2!) whilst DS9150 is running Plesk 11.0.9 and MailEnable Standard 6.54 (that is supposed to be compatible).

Any ideas?