SMTP SmartHost issues   

I have an Exchange 2003 server and I'm forwarding my outbound internet email 
through an SMTP smart host, i.e. the SMTP server provided to me by the web 
hosting company that holds my domain name.

The problem is that outbound authentication is different depending on the 
source address the email originated from.  For instance:

SMTP connector is set to Forwarld all mail through this connector to the 
following smart hosts: mail.mydomain.com

Outbound Security -> Basic authentication -> User = bob@mydomain.com 
(password is set up)

This is fine when bob wants to send an email, it goes through.

Unfortunately, when Jim wants to send an email from jim@mydomain.com it 
bounces straight back to his client with the following error:

"Sender address rejected: not owned by user bob@mydomain.com"

Basically the web-host and controller of the SMTP smart host I'm forwarding 
mail through demands that I log in with the username I'm trying to send 
email from.  I cannot log in with bob@mydomain.com and send email 
originating from someone other than bob@mydomain.com.


Is there some way I can get Exchange 2003 to authenticate to the SMTP 
smarthost with different usernames depending on who the email is from?


Thanks,
Alex

date: Fri, 22 Feb 2008 16:27:58 -0600   author:   Alex Clark

Re: SMTP SmartHost issues   

Alex Clark  wrote:
> I have an Exchange 2003 server and I'm forwarding my outbound
> internet email through an SMTP smart host, i.e. the SMTP server
> provided to me by the web hosting company that holds my domain name.
>
> The problem is that outbound authentication is different depending on
> the source address the email originated from.  For instance:
>
> SMTP connector is set to Forwarld all mail through this connector to
> the following smart hosts: mail.mydomain.com
>
> Outbound Security -> Basic authentication -> User = bob@mydomain.com
> (password is set up)
>
> This is fine when bob wants to send an email, it goes through.
>
> Unfortunately, when Jim wants to send an email from jim@mydomain.com
> it bounces straight back to his client with the following error:
>
> "Sender address rejected: not owned by user bob@mydomain.com"
>
> Basically the web-host and controller of the SMTP smart host I'm
> forwarding mail through demands that I log in with the username I'm
> trying to send email from.  I cannot log in with bob@mydomain.com and
> send email originating from someone other than bob@mydomain.com.
>
>
> Is there some way I can get Exchange 2003 to authenticate to the SMTP
> smarthost with different usernames depending on who the email is from?
>
>
> Thanks,
> Alex

Nope, sorry. If you must use a smarthost instead of sending out directly,
I'd find a different provider. Unless you've got a dynamic IP, etc., you're
best off sending out directly, resolving recipient domains via DNS.

NB: The Exchange 2000 groups are pretty stale - Exchange questions are best 
asked in m.p.exchange.* instead (always mention your version & SP level in 
there as answers frequently vary by version).

date: Fri, 22 Feb 2008 22:42:33 -0500   author:   Lanwench [MVP - Exchange]