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VuthyNhek-0705 avatar image
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VuthyNhek-0705 asked AndyDavid commented

Exchange 2016 server IP Address

Hi,

We are hosting our Exchange 2016 server on the premise. When email going out, instead of showing the email coming from the Exchange server IP address, its shown it's from our firewall ip address. For this reason, we have our emails blocked by some recipients' email servers.

We have PTR records of our firewall and Exchange server ip addresses point to our domain name, but still some emails got rejected because of it, especially emails go to msn.com and live.com etc.

Any comment or suggestion will be greatly appreciated.

Thanks

Tee

office-exchange-server-mailflow
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it shouldnt show the Firewall IP unless you are doing something at the firewall or the firewall is acting as a smarthost.
The PTR Record shouldnt be pointing at your domain name, it should be the public FQDN of the Exchange Server

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ZhengqiLou-MSFT avatar image
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ZhengqiLou-MSFT answered

Hi @VuthyNhek-0705 ,

Please also check the settings of your Send Connectors if they are set to use the smart host.
And try disabling it and using the default/mx record to route mails if there is a smart host send connector.

Best regards,
Lou


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VuthyNhek-0705 avatar image
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VuthyNhek-0705 answered

Andy,

Thanks for your response. Correction, I meant the PTR record is pointing to our public FQDN of the Exchange server.

I have checked with the firewall support and they have found nothing that indicated the firewall is acting as a smarthost. I will try to reach out to firewall support again.

Thanks

Tee

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VuthyNhek-0705 answered

Lou,

@ZhengqiLou-MSFT

This is our "Send Connect" in "delivery" setting:

Selected - MX record associated with recipient domain

None - Smart host authentication

Last couple days, the outgoing mails is shown coming from the Exchange server instead of firewall. I don't know what has changed, but all of sudden, it's shown correctly.


Thanks for all your help.

Tee

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