How to get SMTP server name through PowerShell when $PSEmailServer is empty? - powershell

Question

Windows 7, PowerShell 4.0. Computer is in the Windows domain.
I need to get SMTP server name (for using of the send-mailmessage cmdlet). The $PSEmailServer is empty.
I read this TechNet page about the Get-AcceptedDomain cmdlet. But I see this (on the TechNet page):
This cmdlet is available in on-premises Exchange Server 2016 and in
the cloud-based service.
How can I get SMTP server name or its IP-address?

Answer 1

If properly defined, the SMTP server address, either host name or IP, can be set through the SCP record in AD or Autodiscover DNS record of Exchange Server. There is a Powershell solution for querying SCP but Autodiscover solution is shorter, so I'll go on with it.
This works on Exchange Server 2010 and later. It should work with Exchange Server 2007 also but personally I have never used it.
You can get the host name;
$MailServer = [Net.DNS]::GetHostByAddress([Net.DNS]::GetHostEntry("Autodiscover").AddressList[0]).Hostname
or IP address (as string);
$MailServer = [Net.DNS]::GetHostByAddress([Net.DNS]::GetHostEntry("Autodiscover").AddressList[0]).AddressList[0].IPAddressToString
Since the GetHostByAddress(string) returns an instance of class System.Net.IPHostEntry, you can have some properties to make use of. For details, please read Microsoft Docs.
PS: I know, that's not the best practice to use the index of integers for values, but AddressList is an array of strings. So it does not define a method such as FirstOrDefault() or a property like DefaultAddress. So far, that is the most optimal and practical solution AFAIK.

Answer 2

Assuming the computer is member of a domain with Exchange deployed, and you want to use Exchange as STMP relay for send-mailmessage, you could ask the exchange configuration in the AD Configuration Context:
import-module activedirectory
$ag = "Exchange Administrative Group (ABCDEFGHIJKLM)" #enter your EAD
$c = "Acme" # Enter your company name (get this form ADSIEdit if unknown)
$sb = ("CN=Servers,CN=" + $ag + ",CN=Administrative Groups,CN=" + $c + ",CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=staff,DC=hsrw")
$server = Get-ADObject -Properties cn, msExchSMTPReceiveConnectorFQDN, msExchSmtpReceiveBindings, msExchSMTPReceiveInboundSecurityFlag -SearchBase $sb -filter { objectClass -eq "msExchSmtpReceiveConnector"}
$server | ft cn, msExchSMTPReceiveConnectorFQDN, msExchSmtpReceiveBindings, msExchSMTPReceiveInboundSecurityFlag
This will spit out the hostnames and port bindings of every receive connector in your organisation. You then have to choose which one to use.
As I don't know how much Exchange knowledge you have, I will stop here. If something's unclear, just ask.