Receiving "530 authentication required for relay" email replies

When emailing different companies, we receive intermittent bouncebacks.  These are few, about 1-2 a week that I am aware of, and many times from the same company (different people), but not always.

The error is:
The following recipient(s) could not be reached: on 8/6/2007 10:30 AM
            There was a SMTP communication problem with the recipient's email server.  Please contact your system administrator.
            < #5.5.0 smtp;530 authentication required for relay (#5.7.1)>

We are running SBS 2003 with Exchange.  I'm not knowledgeable in Exchange or email, and not sure where to start to diagonse this problem.  Thank you!
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SembeeConnect With a Mentor Commented:
Exchange can send email in one of two ways.
Directly by doing DNS lookups.
Indirectly via another SMTP server, which Exchange/Microsoft refer to as a smart host.

If you run the Internet and Email connection wizard (or whatever it is called) there is an option in there about sending email through the ISPs server (or not). You need to see if that is completed or not.

Otherwise it is looking at the SMTP logs for failures to see if you can find a pattern.

Do you send email email directly or via a smart host?
If via a smart host then you need to speak to whoever server it is as it is their server that is rejecting your message.

RepicheepAuthor Commented:

I would say that we send email directly, but I'm not totally sure what you are asking.  I don't know what a "smart host" is or does.  (Would that be Alex Trebek).  jk

We are using SpamSoap for incoming email only.  Outgoing should be going directly out.

Thanks,   Steve
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RepicheepAuthor Commented:
Simon,    Thanks for the direction.  I'm fairly sure we are not sending email through an ISP server, but checking the SMTP logs is a great idea.  I'll see what I can find in the logs when I return.

Forced accept.

EE Admin
Did the internet and email connection wizard do the trick for this?
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