Exchange 2003 IMAP clients cannot send email recieve error 454 5.7.3 Client does not have permission to send as this sender

Posted on 2005-04-10
Last Modified: 2012-06-27
Runing Outlook 2003 and trying to send an email message I get this:

The message could not be sent because the server rejected the sender's e-mail address. The sender's e-mail address was ''. Subject 'test', Account: 'ACCOUNT NAME', Server: 'FQDN', Protocol: SMTP, Server Response: '454 5.7.3 Client does not have permission to Send As this sender.', Port: 25, Secure(SSL): Yes, Server Error: 454, Error Number: 0x800CCC78

This was working last week and I'm not sure what has changed. We just recently migrated our first site to e2k3 my old 5.5 server is still running since it was the first in the organization and my other two sites have not yet been migrated to e2k3.

I checked the account settings in outlook and it does have the correct email address specified for the account and I also recieve a similar error if I configure the account in Outlook Express.

The server I am trying to talk with is an Exchange 2003 sp1 front end server which should only be allowing encrypted/authenticated connections for external users. I already have another smtp relay accepting and delivering anonymous email connection for the organizaiton.

The frontend server requires Basic/TLS authentication and the backend uses basic authentication without requiring TLS as well as integrated windows auth and anonymous auth.

Ports 443/TCP, and 25 are allow to the Front End servers external IP address

The front end is allowed to talked with the backend exchange server on ports:
80/TCP, 6001, 6002, and 6004/TCP, ICMP, 691/TCP, 143/TCP

The Front end server is allowed to talk to the DC/GCs on ports:
53/UDP, 88/TCP & UDP, 135/TCP, 389/TCP & UDP, 3268/TCP, 445/TCP, STATIC RPC PORT/TCP, 123/TCP
Question by:Annubiz

    Author Comment

    We found the problem: An enterpising network admin had entered an entry in the "maskarade" field in the advanced area of the outbound security tab of the smtp virtual server on the Front end server.  This was causing the from address to be translated to his entry and when the frontend server when to compare the authenticated creditials against the submitting email address the email address that it was passing did not match the account that had authenticated.

    Accepted Solution

    The question has been PAQ'd and the 500 points have been refunded.
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