Outbound Ipv4 Configuration
Question asked by Matt Lyons - 10/11/2022 at 10:53 PM
I am hosting SM on an Azure VM. I have added a second IP address and it's private IP address is listed in the domains Outbound IPv4 dropdown (along with the primary IP address's private IP). I select the secondary IP address under the domain configuration and I under the server Settings, Protocols, SMTP Out, Outbound IPv4 I have "Use the Domain's IP" selected. But when I send email from this domain I still see the primary IP address in the received email's headers. Anyone know what else I am missing?

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Zach Sylvester Replied
Employee Post
Hey Matt, 

It sounds like you might need to do a couple of things. 
  1. Make sure that port 25 is open on that IP. 
  2. Make sure that port 25 is selected for that IP in Settings->Bindings->ports

If both of these things are true you can try rebooting the server to reset the NIC. 

Please let me know if this helps. 

Kind Regards, 
Zach Sylvester System/Network Administrator SmarterTools Inc. (877) 357-6278 www.smartertools.com
Matt Lyons Replied
Thanks Zach,

Port 25 is open for Any source and destination in the firewall. And IP address also checked for port 25.

I found this in the logs so I think this means the problem is probably with the Azure IP configuration:

[2022.10.12] 05:10:01.812 [55057213] Initiating connection to
[2022.10.12] 05:10:01.812 [55057213] Connecting to (Id: 1)
[2022.10.12] 05:10:01.812 [55057213] Binding to local IP (Id: 1)
[2022.10.12] 05:10:01.812 [55057213] Exception connecting to (Id: 1)
[2022.10.12] 05:10:01.812 [55057213] System.Exception: Exception: Connection failed
[2022.10.12]    at MailService.RelayServer.Clients.SMTP.ClientConnectionSync.Connect(Int32 connectionId, Int32 timeout)05:10:01.812 [55057213] Previous connection attempt failed. Attempting again with primary local ip.
[2022.10.12] 05:10:01.812 [55057213] Connecting to (Id: 2)
[2022.10.12] 05:10:01.828 [55057213] Connection to from succeeded (Id: 2)
[2022.10.12] 05:10:02.062 [55057213] RSP: 220 mx.google.com ESMTP n8-20020a63b448000000b0045c88c3b799si17066466pgu.709 - gsmtp
Now I see that the new NIC says "No network access" and it is missing a default gateway. 

I will poke around the Azure settings and reboot the server later tonight.

Thanks for the suggestions. 
Matt Lyons Replied
UPDATE: I was able to add a default gateway on the second NIC by running a "route" command at the dos prompt. The second public IP address can now be used for the Outbound IP.

I got the route command from this page:
(this was really hard to find.)
Matt Lyons Replied
UPDATE 2: The default Outbound IPv4 setting is Automatic. This means that as soon as you add a second IP address SmarterMail can, and did for me, start using that IP address immediately. I had added a PTR record for this IP address but it hadn't propagated yet so I got lots of bounced emails due to untrusted IP address.

Here are the instructions for adding a PTR record for Azure IP address (note you have to use PowerShell): 
Tony Scholz Replied
Employee Post
Thanks for the update Matt, I am glad that you were able to get this resolved. 
Tony Scholz System/Network Administrator SmarterTools Inc. (877) 357-6278 www.smartertools.com

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