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SMTP duplication

I have a need to either fully duplicate all valid inbound smtp traffic (i.e. clean SMTP conversations) to more than one server (we want to duplicate traffic to our production mail server and a test mail server - in parallel) OR perhaps better still, to be able to selectively redirect a few individual email accounts withint the email domain to the test mail server. It would be good if this was possible within CSVB as this is our first smtp point of contact for inbound smtp traffic.

Alternatively if we need to install an smtp proxy server inbetween CSVB and the two mail servers, and get the smtp proxy to somehow duplicate the traffic in parallel, then that would be good too; but I have spent several hours searching the net and not really found any answers. Suggestions very welcome!

There are service providers out there providing mx backup servers (simple store and forward), but some of these add the extra facility of being able to give access to the temporary spool/queue of email  via webmail, but without removing the viewed email from the queue; so that when the primary mail server is back up again, all emails are still received at the primary mail server. I am assuming that this is done by keeping a queue separate for sending off to the primary in due course, and a duplicate queue which can be queried via webmail. Hopefully you can see that the requirements of what is needed in the first paragraph could be very similar to the implementation above.

Many thanks.


Re: SMTP duplication

Hello Paul,

to be honest, I do not think that your scenario can easily be achieved with an CSVB. The only way I could think of would be to use a content filter with a 'Send Copy (BCC)' action on it,  which will send a copy to the second mail server (which accepts messages for a different domain name that is used in the BCC address then). Using an SMTP Route for this BCC domain, the message is redirected to your second mail server.

There are several downsides to this solution, such as that the secondary mail server needs to accept the BBCd message as well as invoking a second domain name (which does not necessarily need to exist in real/internet world). Also all messages seen by the content filter will be BCCd to the same recipient BCC address.

Hope this helps. If not, please feel free to post back.



Community Member

Re: SMTP duplication

Thanks for your suggestion. In the end I simply let CSVB route email through to the primary mail server as usual and simply set up mailbox based rules to forward a copy of the email to the same user on the parallel test email domain on the secondary mail server.

Although not ideal, as it required a system wide email forwarding rule change on the primary mail server, this is working well.

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