question about exchange send connector ?

Question

I have a little bit confuse about the "scoped send connector " and "source servers" setting on send connector.
first of all, I think I know what they mean, okay ...may be I don't really know....haha
lets take a example:
if we have 2 AD site, one in China, and one in US, each site have 1 exchange 2016.

Scenario A:
create a send connector (no scoped) and add China exchange as source server. (address space is wildcard)
create a send connector (no scoped) and add US exchange as source server. (address space is wildcard)

Scenario B:
create a send connect (scoped) and add 2 exchange servers as the source server.

quesiton:
what the different between scenario A and B ?

I want the outbound server location to be the same as the mailbox database server location for the account, for example a China account will send from China server and a US account will send from the US server. which scenarios can do that ?

sorry about my terrible english...and thanks!

Answer 1

Hi,

By default, Send Connectors are used by all the Exchange servers in the entire AD forest, and are used in routing decisions. Send connectors will be created to route email messages to external and these are at organization level. Source servers will be added to the Send connector. This means that only servers which are added as source server in the send connector can use that connector to send emails to internet. Lets say there are 2 exchange servers EXCH1 & EXCH2. EXCH1 is added as the source server to the Send connector. This means that all external emails will be sent by server EXCH1 and if any user sends email from EXCH2 that will be routed to EXCH1 and will be sent out. This is because the EXCH2 knows that the send connector is configured with EXCH1.

On the other hand, scoped send connector controls the visibility of the connector within the Exchange organization. Scoped Send connector is only usable by other transport servers in the same Active Directory site.

In Scenario A, since Send connectors are not scoped and with same address space, it will be visible to the entire AD forest and Exchange will use based on the connector selection methods if both servers are part of the same DAG.

In scenario B, if the send connectors are scoped, then it is visible only to that AD site and cannot have source server from a different site.

For your scenario, you can create 2 Scoped send connectors and add the respective source server. For China, one scoped send connector with china exchange server as source server and for similarly for US, scoped send connector with US Exchange server as source server.

https://learn.microsoft.com/en-us/exchange/mail-flow/mail-routing/connector-selection?view=exchserver-2019
https://letsexchange.blogspot.com/2016/11/what-is-scoped-send-connector.html

Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

If the above suggestion helps, please click on "Accept Answer" and upvote it. Thanks for understanding.

Answer 2

Ok, lets look at each case:

Scenario A:
create a send connector (no scoped) and add China exchange as source server. (address space is wildcard)
create a send connector (no scoped) and add US exchange as source server. (address space is wildcard)

In this scenario, each send connector can be seen and used by any mailbox server in the org to route mail through. This is generally the recommended setting - to leave the default.
So in other words, even though one send connector has just the US server as the source server, the server in China can still see it and send mail out through it using the US server as the source.

Scenario B:
create a send connect (scoped) and add 2 exchange servers as the source server.

This configuration would not make sense in your case. With 2 servers and 2 sites , this is the same as having one unscoped send connector with both source servers.
In fact, I suspect Exchange would throw an error if you tried to configure it this way.

Bottom Line: If Scoped - only the servers in the same AD site as the source servers can see and use the send connector. Servers outside that AD site will NOT be able to see it exists.

Make sense?

This may help as well:
http://clintboessen.blogspot.com/2014/01/what-are-scoped-send-connectors.html

Answer 3

@Jerry Su
Hi,

The "Scope" controls whether the send connector is visible to other exchange servers.
If a send connector is scoped,it can only be used by exchange servers in the same site.
If it is not scoped,it can be used by all exchange servers in your environment.

The "Source servers" determines the destination Exchange server for mail that needs to be routed through the Send connector.
For example,if you configure a send connector to send mails to the internet and add only one server to the "Source servers",the other servers will route outbound mails to this server.
And only through this server are outbound mails sent to the internet.

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In Scenario A,since the send connector are not scoped,the two servers can use both send connectors to send mails.
For example, if "send connector A" is configured to send mails to domain "contoso.com" and its source server is the server in China.
The server in US will route mails to the server in China if the mails are supposed to be sent to "contoso.com".
Then the server in China will send the mails to "contoso.com".

In Scenario B,I think it you may get a warning of adding servers in different sites to source servers of a scoped send connector,as server in a different site isn't able to see the send connector.

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I want the outbound server location to be the same as the mailbox database server location for the account, for example a China account will send from China server and a US account will send from the US server. which scenarios can do that ?
You may need to configure two scoped send connectors and add the specific server in China or US as the only source server to each of them.
So the mails won't be routed to the other server.

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Answer 4

hi Andy and Ashok, both answers are very clarity. thanks!