Update Set-EmailAddressPolicy.md

This PR is an update to my PR MicrosoftDocs#6324 I submitted Aug 14, 2020. This PR fixes an omittance in the PowerShell code of Example 3, changes the code to use double quotes to be consistent with other examples, and makes the explanation wording more clear.

Author: dbird03

exchange/exchange-ps/exchange/Set-EmailAddressPolicy.md

@@ -88,10 +88,10 @@ In on-premises Exchange, this example clears the disabled email address template
 
 ### Example 3
 ```powershell
-Set-EmailAddressPolicy -Identity 'Office 365 Groups' -EnabledEmailAddressTemplates "SMTP:@contoso.com","@contoso.onmicrosoft.com","smtp:@contoso.microsoftonline.com"
+Set-EmailAddressPolicy -Identity "Office 365 Groups" -EnabledEmailAddressTemplates "SMTP:@contoso.com","smtp:@contoso.onmicrosoft.com","smtp:@contoso.microsoftonline.com"
 ```
 
-In Exchange Online, this example modifies the existing email adress policy named Office 365 Groups by setting the enabled email address templates to "SMTP:@contoso.com", and "@contoso.onmicrosoft.com", and "smtp:@contoso.microsoftonline.com". This will also set the enabled primary SMTP address template to "@contoso.com".
+In Exchange Online, this example modifies the existing email adress policy named "Office 365 Groups" and sets the enabled email address templates to use "@contoso.com" as the primary SMTP address and "@contoso.onmicrosoft.com" and "@contoso.microsoftonline.com" as proxy addresses.
 
 ## PARAMETERS