error message: 550 No such user - psmtp but the user account is there

Posted on 2009-02-09
Last Modified: 2012-06-27
We have had exchange working for a couple of years, but now all of the sudden we get an error saying 550 no such user. This error is not on all accounts but just a few. It is going through postini. What would cause it to mess up all of the sudden.
Question by:lawrencex
    LVL 17

    Expert Comment

    I guess the issue is "Sending mails Out of the exchange server to Internet right?"
    what about the internal users? are you able to do a self mail ?
    is this happenning for all the External domains or few of them?
    LVL 65

    Accepted Solution

    Is this inbound or outbound email?
    If it is inbound and the error has PSTMTP on it, then the problem is with Postini, you will need to take it up with them.


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