I have developed an ASP.Net web application from which I want to send an email on behalf of the currently logged in user.

When attempting this I get the error message:

Mailbox unavailable. The server response was: 5.7.1 Client does not have permissions to send as this sender

Does anyone know how to get round this?

We are using:
.net 2.0
iis 6
windows server 2003

Not sure about the emailing setup, I've asked the technical people there to have a look but I'm asking this question now so I can try to understand the problem.



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i looked on u r issue and found that firstly u have to create mailbox on u r mailserver .

i am no nearer to solving this problem
i can only send emails if i hard code the user name and password of an authenticated user into the code that sends the email?!
i need it to send an email on behalf of whichever user is logged in
maybe this is a question for the asp.net forum, seems i have drawn a blank here!

one last go at this...

has ANYONE here any experience of SMTP / authentication etc?!


Hi David,

have you enabled relaying between your webserver and mailserver?

No, I haven't done anything to the mail server.
I am able to send emails from my asp.net pages.
Emailing works.
The question is, why does a mail server need to be setup to require authentication when it's only used by the company. It makes it impossible to use unless you pass the details of each user (name and password) each time you want to send something on their behalf!
I have abandoned that approach and now only send from generic accounts e.g. 'sales@' for which I know the authentication details.

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