relaying denied

[steve]

I often receive messages from the System Administrator
(I'm only using the client side version of Outlook, i.e.
there is no exchange server) when replying to or
forwarding legitimate emails with

Subject: Undeliverable

and message body that says

"550 5.7.1 <recipientname>... Relaying denied. Proper
authentication required.."

Does anyone know why I am receiving these messages and how
I can eliminate them. Thanks in advance for any help you
can provide.

 

[Lanwench [MVP - Exchange]]

Check your mail account settings to make sure you're set up to authenticate
to your SMTP server. Check with your ISP if you aren't sure what they need.

 

[Jeff Stephenson [MSFT]]

http://office.microsoft.com/assistance/preview.aspx?AssetID=HA011128331033
discusses this.