Update Set-MailUser.md

Author: dariomws

exchange/exchange-ps/exchange/users-and-groups/Set-MailUser.md

@@ -740,6 +740,8 @@ To specify the primary SMTP email address, you can use any of the following meth
 
 - Use the PrimarySmtpAddress parameter instead. You can't use the EmailAddresses parameter and the PrimarySmtpAddress parameter in the same command.
 
+The PrimarySmtpAddress parameter updates the primary email address and WindowsEmailAddress property to the same value.
+
 To replace all existing proxy email addresses with the values you specify, use the following syntax: "\<Type\>:\<emailaddress1\>","\<Type\>:\<emailaddress2\>",..."\<Type\>:\<emailaddressN\>".
 
 To add or remove specify proxy addresses without affecting other existing values, use the following syntax: @{Add="\<Type\>:\<emailaddress1\>","\<Type\>:\<emailaddress2\>",...; Remove="\<Type\>:\<emailaddress2\>","\<Type\>:\<emailaddress2\>",...}.
@@ -1391,6 +1393,8 @@ By default, the primary address is the same as the ExternalEmailAddress paramete
 
 If you set the EmailAddressPolicyEnabled parameter to $false, you can specify the primary address using the PrimarySmtpAddress parameter, but that means the email addresses of the mail user are no longer automatically updated by email address policies. We recommend that you don't set the primary email address to a value other than the ExternalEmailAddress unless you're in a cross-forest scenario.
 
+The PrimarySmtpAddress parameter updates the primary email address and WindowsEmailAddress property to the same value.
+
 ```yaml
 Type: SmtpAddress
 Parameter Sets: (All)