Lefty.Email 0.2.0

lemail

.NET tool to send emails through SMTP, Resend, or Azure Communication Services.

Installing

To install the tool as a repository tool, run the following command in the root of your repository:

> dotnet tool install --local Lefty.Email --create-manifest-if-needed

If you'd rather have the tool installed globally in your machine, run the following command:

> dotnet tool install --global Lefty.Email

Senders

When using smtp sender (default):

When using resend sender:

> set EMAIL_SENDER=resend
> set RESEND_APITOKEN=<api>

When using acs sender (Azure Communication Services):

Exactly one of ACS_CONNECTIONSTRING or ACS_ENDPOINT must be set.

> set EMAIL_SENDER=acs
> set ACS_CONNECTIONSTRING=endpoint=https://<resource>.communication.azure.com/;accesskey=<key>

When ACS_ENDPOINT is set, the tool authenticates using DefaultAzureCredential, which supports managed identity, workload identity, environment variables and developer credentials (such as az login). For a user-assigned managed identity, set AZURE_CLIENT_ID to the client id of the identity. The identity must be granted a role with permission to send email on the Communication Services resource.

> set EMAIL_SENDER=acs
> set ACS_ENDPOINT=https://<resource>.communication.azure.com/

Note that ACS ignores the display name of the sender: the sender address must be a MailFrom address of a domain linked to the resource, and the display name is configured there.

Example

The tool accepts a single argument, which is the name of a Json file.

> cat email.json
{
   "from": "Master Yoda <yoda@dagobah.sw>",
   "to": "Luke Skywalker <lskywalker19@tatooine.sw>",
   "subject": "Reminder",
   "htmlBody": "<h1>Use the force</h1>"
}
> dotnet lemail email.json

It is also possible to pipe JSON to the command:

> cat email.json | dotnet lemail --stdin

Usage patterns

The tool supports all of the following usage patterns to construct the email message to send:

• JSON (file, or piped in)
• Environment variables, only if --env is provided)
• CLI options

Json format

The format of the file is as follows:

An Email can be expressed as follows:

• lskywalker19@tatooine.sw - Just the e-email address
• Luke Skywalker <lskywalker19@tatooine.sw> - With display name

Environment variables

The following variables will be evaluated, but only if --env option is provided in the command line.

CLI options

> dotnet lemail --help
Email sender

Usage: lemail [options] <InputFile>

Arguments:
  InputFile       Input JSON file

Options:
  --version       Show version information.
  -f|--from       Sender email address
  -t|--to         Recipient email address
  -s|--subject    Subject
  -h|--html-file  HTML file
  -x|--text-file  Text file
  -X|--text       Text content
  --stdin         Read JSON from stdin
  -e|--env        Load sender/recipient from environment variables
  -?|--help       Show help information