iis smtp nntp: Hi,
I am trying to send mail using IIS 5.0 SMTP using different outbound IP
addresses, but it's not working. I have one network interface on the server
which is multihomed with 2 IP addresses. The "default" IP address for the
interface is assigned to the default virtual SMTP server. I added a 2nd
virtual SMTP server configured exactly like the default, and assigned the
2nd IP address to it.

I can successfully connect to and relay mail via the new virtual server,
however, the IP address IIS uses when connecting to the destination SMTP
server is *always* that of the default virtual server.

I have disabled socket pooling per some other posts, however that did not
make any difference. Am I missing something here? I can't be the first
person who's needed to do this!?

Any assistance is much appreciated!

Regarding socket pooling, yes, i was aware it is for listening, however
nothing else was working and so i tried it to see if it had any impact.

Yes, changing the default IP address (the one listed on the first page)
in the network properties does change the IP address SMTP uses when
sending. So you are correct, IIS SMTP indeed has no control over which
IP is used when sending.

We have since determined that all of this is indeed a TCP/IP routing
issue. Even using multiple NICs connected to different networks with
SMTP VS's bound to each doesn't help, since it's the interface tied to
the default route (view with 'route print') that's always going to be
used.

The only solution we have come up with is using Microsoft Virtual Server
to run a separate instance of the OS and IIS/SMTP, in which case we have
completely distinct network settings and can adjust the default route
accordingly. The downside is that there is obviously more overhead
involved here than simply adding a new SMTP VS and/or NIC...the upside
is that we don't have to add new server hardware simply to run a
distinct SMTP server.

GregG



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Socket Pooling is for listening for incoming connections, not for sending
mail out.

If you change the order of IP addresses bound to the network card in Network
Properties, does the behaviour change? If so, then this isn't under the
control of MS SMTP server...

Cheers
Ken

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