jitesh-raut/azure-email-communication-service-for-sending-emails

Purpose and Entry Points

This is a small Python sample repository for sending email through Azure Communication Services (ACS). It demonstrates two independent execution paths:

• ACS Email SDK client: SendEmail_ACS_EmailClient.py

• Standard SMTP submission: SendEmail_ACS_SMTP.py

README.md is the operational guide for provisioning Azure resources, linking a verified domain, and configuring credentials.

Azure Resource and Domain Boundary

Before either sender can work, Azure infrastructure must exist: an Email Communication Service, an Azure Communication Service resource, and a verified/managed email domain connected to ACS. The sender address must belong to that connected domain.

The repository does not provision infrastructure programmatically; these are manual Azure Portal steps documented in README.md.

SDK-Based Email Send Path

SendEmail_ACS_EmailClient.py uses the Azure Communication Email Python SDK and connection-string authentication. Its primary flow is:

1. Create EmailClient from an ACS connection string.

2. Construct an email payload with sender, recipients, subject, and plaintext content.

3. Call the asynchronous begin_send operation.

4. Block on the returned poller for the send result.

This path crosses directly from the local Python runtime to the ACS Email API, with authentication bounded by the ACS connection string.

SMTP-Based Email Send Path

SendEmail_ACS_SMTP.py uses Python’s SMTP/email libraries to submit a MIME message. Its control flow is:

1. Build a multipart MIME email and populate headers/body.

2. Open an SMTP connection to ACS.

3. Upgrade the connection with STARTTLS.

4. Authenticate and submit the serialized message.

5. Close the SMTP session.

The remote SMTP boundary is smtp.azurecomm.net on port 587, with TLS 1.2+ required.

Identity and Authorization for SMTP

SMTP authentication uses Microsoft Entra application credentials rather than an ACS connection string. The SMTP username combines ACS resource name, Entra application ID, and tenant ID; the password is an Entra client secret.

The Entra service principal needs ACS permissions equivalent to Communication Services read and Email Services write. Role assignment and credential lifecycle are external Azure/Entra operational concerns described in README.md.

Data Flow and Operational Constraints

Both paths accept equivalent logical data: verified sender address, recipient address(es), subject, and message content. They differ only at the delivery transport/authentication boundary:

• SDK payload and ACS connection string: SendEmail_ACS_EmailClient.py

• MIME serialization, SMTP/STARTTLS, and Entra credentials: SendEmail_ACS_SMTP.py

Scripts are intended for local Python execution and use placeholder values that must be replaced before use. The SDK route requires the azure-communication-email package; SMTP relies on Python standard-library modules.