Merge pull request #287757 from davegoddard/patch-1

Changing authenticated relay recommendation to 1P service ACS

Author: prmerger-automator[bot]

articles/virtual-network/troubleshoot-outbound-smtp-connectivity.md

@@ -19,9 +19,9 @@ Outbound email messages that are sent directly to external domains (such as outl
 
 ## Recommended method of sending email
 
-We recommend you use authenticated SMTP relay services to send email from Azure VMs or from Azure App Service. (These relay services typically connect through TCP port 587, but they support other ports.) These services are used to maintain IP and domain reputation to minimize the possibility that external domains reject your messages or put them to the SPAM folder. [SendGrid](https://sendgrid.com/partners/azure/) is one such SMTP relay service, but there are others. You might also have an authenticated SMTP relay service on your on-premises servers.
+We recommend you use authenticated SMTP relay services to send email from Azure VMs or from Azure App Service. Connections to authenticated SMTP relay services are typically on TCP port 587 which is not blocked. These services are used in part to maintain IP reputation which is critical for delivery reliability. [Azure Communication Services](/azure/communication-services/overview) offers an [authenticated SMTP relay service](/azure/communication-services/quickstarts/email/send-email-smtp/smtp-authentication). Ensure that the [default rate limits](/azure/communication-services/concepts/service-limits#rate-limits) are appropriate for your application and open a support case to raise them if needed.
 
-Using these email delivery services isn't restricted in Azure, regardless of the subscription type.
+Using these email delivery services on authenticated SMTP port 587 isn't restricted in Azure, regardless of the subscription type.
 
 ## Enterprise and MCA-E