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Can I direct all SMTP traffic over a specific gateway?

- Small Business Server 2000
- Gateway 1 : Fixed IP, 1/2 meg connection  :
- Gateway 2 : Dynamic IP, 4 Meg connection :

Gateway 2 is new and very quick compared to gateway 1.

I Switched the server's gateway over to gateway 2 and found that many emails sent from the business were returned as the recipient won't trust smtp mails from a dynamic IP.  

I want to utilise gateway two as fully as possible.

Is there any way i can direct all SMTP traffic over to gateway 1 whilst using gateway 2 for all other internet traffic?

I've added gateway 2 as a second gateway with the same metric as gateway 1, and sometimes it seems to utilise gateway 2 - I've done speed tests which prove this - but also I've done speed tests which show only 1/2 meg usage.

I've also blocked port 25 on Gateway 2's firewall so when mail does go out, it has to go through gateway 1.

When I put gateway 2 as the primary gateway, mail ends up queing in the exchange system.
When I put gateway 1 as the primary gateway, bandwidth from gateway 2 is not always utilised

Any input would be gratefully recieved!
Windows Networking

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Keith Alabaster

8/22/2022 - Mon
Keith Alabaster

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Thanks for the reply,
  thats exactly what I needed to know, basically that its not going to work!

I have re-set the gateway back to the original state and I'm going to look in to boosting that pipe's bandwidth, and use the new pipe for another project entirely.

Keith Alabaster

You are welcome.

to correct the issue where the emails bounce because your connection 2 is untrusted, set the GW for connection 2 and in exchange use a SMTP connector to send all messages via a smart host.  The smart host will be the connection 2 ISP provided email server.  Look on your config sheets for ISP2 and whatever you are suposed to use for SMTP server name, make that the smarthost.
Your help has saved me hundreds of hours of internet surfing.

carl, I will try that, thanks for the input.  I have not used Smart hosts before.

the premise is hopefully easy to digest.  Your ISP provides mail out and in to all of its users. They all have to.  what if you are one guy with one machine and plug in to thier service.  You tell outlook express for example that to GET mail, the pop3 server is mail.isp.com and to send mail the SMTP server is mail.isp.com.
Somewhere all internet providers have these servers.  The have the same likelyhood of being blacklisted for spam as any other mailserver on the net, except for two reasons- they have their own filters to evaluate if you are sending spam and will shut of just you when exceede thier threshold of spam.  Second, if the server is blacklisted, there is someone who works for the ISP that will quickly make the requests to remove it from the blacklist.

You can program exchange or any other mail server to not try to send mail directly, but through the ISP's mail server, thus reducing who thinks those messages are spam.
Keith Alabaster

Thank you :)
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