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Email Communication Service Test Report

1. Overview

The purpose of this test was to validate Azure Communication Services (ACS) Email functionality end-to-end using the Python SDK. The scope included resource provisioning, sending various email types, delivery confirmation, and monitoring.

  • Date: April 14, 2026
  • Tester environment: Azure CLI + Python 3.12 + azure-communication-email==1.1.0

2. Resource Provisioning

All resources were created in the rg-acs-email-lab resource group (koreacentral).

Resource Name Type
Resource Group rg-acs-email-lab Microsoft.Resources/resourceGroups
ACS Resource acs-email-lab Microsoft.Communication/communicationServices
Email Service ecs-email-lab Microsoft.Communication/emailServices
Email Domain AzureManagedDomain Microsoft.Communication/emailServices/domains
Log Analytics law-acs-email-lab Microsoft.OperationalInsights/workspaces

Provisioning Commands

az group create --name rg-acs-email-lab --location koreacentral

az communication create --name acs-email-lab --resource-group rg-acs-email-lab --data-location "Korea" --location global

az communication email create --name ecs-email-lab --resource-group rg-acs-email-lab --data-location "Korea" --location global

az communication email domain create --domain-name AzureManagedDomain --email-service-name ecs-email-lab --resource-group rg-acs-email-lab --location global --domain-management AzureManaged

# Link domain to ACS (REST API)
az rest --method patch \
  --url "https://management.azure.com/subscriptions/{subscription-id}/resourceGroups/rg-acs-email-lab/providers/Microsoft.Communication/communicationServices/acs-email-lab?api-version=2023-04-01" \
  --body '{"properties":{"linkedDomains":["/subscriptions/{subscription-id}/resourceGroups/rg-acs-email-lab/providers/Microsoft.Communication/emailServices/ecs-email-lab/domains/AzureManagedDomain"]}}'

az monitor log-analytics workspace create --resource-group rg-acs-email-lab --workspace-name law-acs-email-lab --location koreacentral

az monitor diagnostic-settings create \
  --name "acs-diag-all" \
  --resource "/subscriptions/{subscription-id}/resourceGroups/rg-acs-email-lab/providers/Microsoft.Communication/communicationServices/acs-email-lab" \
  --workspace "/subscriptions/{subscription-id}/resourceGroups/rg-acs-email-lab/providers/Microsoft.OperationalInsights/workspaces/law-acs-email-lab" \
  --logs '[{"categoryGroup":"allLogs","enabled":true}]' \
  --metrics '[{"category":"AllMetrics","enabled":true}]'

3. Domain Verification

  • Domain: fc135b5e-3353-4c89-9edb-55b53b59215f.azurecomm.net
  • Sender address: DoNotReply@fc135b5e-3353-4c89-9edb-55b53b59215f.azurecomm.net

Azure Managed Domain

All verification records (SPF, DKIM, DKIM2, DMARC, Domain) were auto-completed by Azure.

4. Email Send Tests

# Test Method Result Message ID Timestamp (KST)
1 Single plain text begin_send() ✅ Delivered ec61511c-95a3-4587-8697-fc4663f396c4 11:20:01
2 CC recipient TO + CC ✅ Delivered 950742ee-ea1e-4ee5-bb19-6fc19e3cb87b 11:20:13
3 File attachment base64 text/plain ✅ Delivered f83d14a1-4293-460f-b066-c084370f30a5 11:20:49
4 Rich HTML html content ✅ Delivered bfa11d8b-9f5d-480a-912b-16dbbe05d0da 11:21:05
5-9 Parallel burst (5) ThreadPoolExecutor ✅ 5/5 Delivered 4a4a, fcbc, 6569, d930, eb34 ~8.4s total

Test Implementation Snippets

Single Plain Text 

message = {
    "content": {
        "subject": "Test Email",
        "plainText": "Hello from ACS Email!"
    },
    "recipients": {
        "to": [{"address": "recipient@example.com"}]
    },
    "senderAddress": "DoNotReply@fc135b5e-3353-4c89-9edb-55b53b59215f.azurecomm.net"
}

CC Recipient 

message = {
    "content": {"subject": "CC Test", "plainText": "Testing CC functionality"},
    "recipients": {
        "to": [{"address": "recipient@example.com"}],
        "cc": [{"address": "cc-recipient@example.com"}]
    },
    "senderAddress": sender_address
}

File Attachment 

message = {
    "content": {"subject": "Attachment Test", "plainText": "See attached file"},
    "attachments": [
        {
            "name": "test.txt",
            "contentType": "text/plain",
            "contentInBase64": "SGVsbG8gV29ybGQ="
        }
    ],
    "recipients": {"to": [{"address": "recipient@example.com"}]},
    "senderAddress": sender_address
}

Rich HTML 

message = {
    "content": {
        "subject": "HTML Test",
        "html": "<html><h1>Hello</h1><p>This is a rich HTML test.</p></html>"
    },
    "recipients": {"to": [{"address": "recipient@example.com"}]},
    "senderAddress": sender_address
}

Parallel Burst 

with ThreadPoolExecutor(max_workers=5) as executor:
    futures = [executor.submit(client.begin_send, message) for _ in range(5)]
    results = [f.result() for f in futures]

5. Delivery Confirmation via Log Analytics

The ACSEmailStatusUpdateOperational table was used to track delivery status.

Column Type Description
CorrelationId string Maps to SDK message ID
DeliveryStatus string Status progression
RecipientMailServerHostName string Target mail server
SenderDomain string Verified sender domain
IsHardBounce string Bounce classification

Observation

All 9 test emails reached Delivered status. Each email generated 3-4 log events tracking status transitions from submission to final delivery.

6. KQL Queries Used

Query 1 - Delivery Status Summary 

ACSEmailStatusUpdateOperational
| where TimeGenerated > ago(1h)
| where DeliveryStatus != ""
| summarize Count = count() by DeliveryStatus
| sort by Count desc
Result: OutForDelivery: 9, Delivered: 9

Query 2 - Per-Message Lifecycle 

ACSEmailStatusUpdateOperational
| summarize StatusChanges = count(), FirstEvent = min(TimeGenerated), LastEvent = max(TimeGenerated) by CorrelationId
| extend DurationSec = datetime_diff("second", LastEvent, FirstEvent)
| sort by FirstEvent asc
Result: Duration 3-6 seconds per message

Query 3 - Delivery Confirmation Details 

ACSEmailStatusUpdateOperational
| where DeliveryStatus == "Delivered"
| project TimeGenerated, CorrelationId, RecipientMailServerHostName, SenderDomain, SenderUsername
| sort by TimeGenerated asc
Result: All 9 delivered to gmail-smtp-in.l.google.com

7. Key Findings

  • Zero Configuration: Azure Managed Domain required no manual DNS configuration.
  • CLI Limitation: Domain linking via CLI was not available; REST API patch was required.
  • Performance: Parallel sends (5 concurrent) completed in ~8.4 seconds total.
  • Log Ingestion: Log Analytics ingestion delay was less than 5 minutes.
  • Latency: The end-to-end email lifecycle (submit to Delivered) took 3-6 seconds.
  • SDK Behavior: Python SDK version 1.1.0 begin_send() returns a poller; calling .result() blocks until terminal status.

8. See Also