Sending CDO mail to external users

[Mike1001]

I managed to send automated e-mails to users within my domain using code from Ron de Bruin (http://www.rondebruin.nl/sendmail.htm - special thanks, Ron!) as a basis.
What I could not manage is sending e-mails to external users (e.g. supplier contacts).

I am getting a runtime error message saying
The server has rejected one or more recipient addresses. The
server response is: 550 5.7.1 Unable to relay for user@external_company.com

Who can help to solve this problem?

Thanks in advance

Mike

[Leith Ross]

Hello Mike1001,

Try posting your question with this group CDO Live. Here is the URL
http://www.cdolive.com/

Sincerely,
Leith Ross

[Mike1001]

Hi Leith Ross,

thanks for the link. Unfortunately, my company applies Blue Coat policy to internet access and I currently don't get access to this web site.

Regards,
Mike

[Mike1001]

I solved the issue myself (actually again using information from Ron de Bruin): apparently, when you send to external users, you have to authenticate yourself.

Mike