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Sending emails using AWS SDK for Go

Written by
Updated at July 14, 2025

In this tutorial, you will learn how to send emails via Yandex Cloud Postbox using the AWS SDK for Go.

To start sending emails:

  1. Get your cloud ready.
  2. Configure a directory for authentication data.
  3. Create and run the application.
  4. Check the result.

If you no longer need the resources you created, delete them.

Get your cloud ready

Sign up in Yandex Cloud and create a billing account:

  1. Navigate to the management console and log in to Yandex Cloud or register a new account.
  2. On the Yandex Cloud Billing page, make sure you have a linked billing account with an ACTIVE or TRIAL_ACTIVE status. If you do not have a billing account, create one and link a cloud to it.

If you have an active billing account, you can navigate to the cloud page to create or select a folder for your infrastructure to operate in.

Learn more about clouds and folders.

The infrastructure support costs include:

Set up resources

  1. Create a service account.
  2. Assign the postbox.sender role to the service account.
  3. Create a static access key for the service account. Save the ID and secret key.
  4. Create an address.
  5. Pass a domain ownership check.

Configure a directory for authentication data

  1. Create a directory to store the authentication data in and navigate to it:

    For macOS and Linux:

    mkdir ~/.aws/

    For Windows:

    mkdir C:\Users\<username>\.aws\

  2. In the .aws directory, create a file named credentials, copy the credentials you got when creating a static access key, and paste them into it:

    [default]
aws_access_key_id = <static_key_ID>
aws_secret_access_key = <secret_key>

  3. Create a file named config with the default region settings and copy the following information to it:

    [default]
region = ru-central1
endpoint_url = https://postbox.cloud.yandex.net

Using environment variables

By default, the AWS SDK for Go uses authentication data from environment variables if they are set. These variables have priority over authentication data from the .aws/credentials file.

The following environment variables are supported:

  • AWS_ACCESS_KEY_ID: Static key ID.
  • AWS_SECRET_ACCESS_KEY: Secret key.

To set environment variables, depending on your operating system, follow these steps:

In the terminal, run this command:

export AWS_ACCESS_KEY_ID=<static_key_ID>
export AWS_SECRET_ACCESS_KEY=<secret_key>

In PowerShell, run:

$Env:AWS_ACCESS_KEY_ID=<static_key_ID>
$Env:AWS_SECRET_ACCESS_KEY=<secret_key>

Create and run the application

  1. Get the application code:

    1. Clone the repository:

      git clone https://github.com/yandex-cloud-examples/yc-postbox-examples
    2. Navigate to the folder in the cloned go/simple/ repository.

    3. Fill out the Sender and Recipient fields in the main.go file:

      • Sender: Sender's email address.

        The sender's email domain must match the one specified in the Yandex Cloud Postbox address you created when getting started. For example, if your verified domain is yourdomain.com, you can use addresses like noreply@yourdomain.com or admin@yourdomain.com but not user@mail.yourdomain.com.

      • Recipient: Recipient's email address, e.g., receiver@domain.com. You will need access to this email address for the next step.

    4. Go to the go/ directory.

    1. Create a directory named postbox-go and open it.

    2. Create a file named main.go and paste this code into it:

      package main

import (
  "context"
  "fmt"
  "net/url"
  "os"

  "github.com/aws/aws-sdk-go-v2/aws"
  "github.com/aws/aws-sdk-go-v2/config"
  "github.com/aws/aws-sdk-go-v2/service/sesv2"
  "github.com/aws/aws-sdk-go-v2/service/sesv2/types"
  transport "github.com/aws/smithy-go/endpoints"
)

const (
  // The sender's address must be verified using Amazon SES.
  Sender = "<sender_address>"

  // Recipient's address.
  Recipient = "<recipient_address>"

  // Email subject.
  Subject = "Yandex Cloud Postbox Test via AWS SDK for Go"

  // HTML text of the email.
  HtmlBody = "<h1>Amazon SES Test Email (AWS SDK for Go)</h1><p>This email was sent with " +
    "<a href='https://yandex.cloud/en/docs/postbox/quickstart'>Yandex Cloud Postbox</a> using the " +
    "<a href='https://aws.amazon.com/sdk-for-go/'>AWS SDK for Go</a>.</p>"

  // Email text for email clients without HTML support.
  TextBody = "This email was sent with Yandex Cloud Postbox using the AWS SDK for Go."

  // Character encoding in the email.
  CharSet = "UTF-8"
)

func main() {
  cfg, err := config.LoadDefaultConfig(
    context.Background(),
  )
  if err != nil {
    fmt.Println("unable to load SDK config, " + err.Error())
    os.Exit(1)
  }

  client := sesv2.New(sesv2.Options{
    Region:             "ru-central1",
    EndpointResolverV2: &resolverV2{},
    Credentials: cfg.Credentials,
  })

  // Building the email.
  input := &sesv2.SendEmailInput{
    Destination: &types.Destination{
      ToAddresses: []string{Recipient},
    },
    Content: &types.EmailContent{
      Simple: &types.Message{
        Subject: &types.Content{
          Charset: aws.String(CharSet),
          Data:    aws.String(Subject),
        },
        Body: &types.Body{
          Html: &types.Content{
            Charset: aws.String(CharSet),
            Data:    aws.String(HtmlBody),
          },
          Text: &types.Content{
            Charset: aws.String(CharSet),
            Data:    aws.String(TextBody),
          },
        },
      },
    },
    FromEmailAddress: aws.String(Sender),
  }

  // Sending the email.
  ctx := context.Background()
  res, err := client.SendEmail(ctx, input)

  if err != nil {
    panic(err)
  }

  fmt.Println(*res.MessageId)
}

type resolverV2 struct{}

func (*resolverV2) ResolveEndpoint(_ context.Context, _ sesv2.EndpointParameters) (
  transport.Endpoint, error,
) {
  u, err := url.Parse("https://postbox.cloud.yandex.net")
  if err != nil {
    return transport.Endpoint{}, err
  }
  return transport.Endpoint{
    URI: *u,
  }, nil
}

type staticCredentialsProvider struct {
  accessKeyID     string
  secretAccessKey string
}

func (s *staticCredentialsProvider) Retrieve(_ context.Context) (aws.Credentials, error) {
  return aws.Credentials{
    AccessKeyID:     s.accessKeyID,
    SecretAccessKey: s.secretAccessKey,
  }, nil
}

    3. Fill out the Sender and Recipient fields in the main.go file:

      • Sender: Sender's email address.

        The sender's email domain must match the one specified in the Yandex Cloud Postbox address you created when getting started. For example, if your verified domain is yourdomain.com, you can use addresses like noreply@yourdomain.com or admin@yourdomain.com but not user@mail.yourdomain.com.

      • Recipient: Recipient's email address, e.g., receiver@domain.com. You will need access to this email address for the next step.

    4. Create a file named go.mod and paste this code into it:

      module postbox

go 1.23

require (
  github.com/aws/aws-sdk-go-v2 v1.36.3
  github.com/aws/aws-sdk-go-v2/config v1.29.14
  github.com/aws/aws-sdk-go-v2/service/sesv2 v1.42.0
  github.com/aws/smithy-go v1.22.2
  github.com/emersion/go-message v0.18.2
)

require (
  github.com/aws/aws-sdk-go-v2/credentials v1.17.67 // indirect
  github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.16.30 // indirect
  github.com/aws/aws-sdk-go-v2/internal/configsources v1.3.34 // indirect
  github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.6.34 // indirect
  github.com/aws/aws-sdk-go-v2/internal/ini v1.8.3 // indirect
  github.com/aws/aws-sdk-go-v2/internal/v4a v1.3.33 // indirect
  github.com/aws/aws-sdk-go-v2/service/internal/accept-encoding v1.12.3 // indirect
  github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.12.15 // indirect
  github.com/aws/aws-sdk-go-v2/service/sso v1.25.3 // indirect
  github.com/aws/aws-sdk-go-v2/service/ssooidc v1.30.1 // indirect
  github.com/aws/aws-sdk-go-v2/service/sts v1.33.19 // indirect
)

  2. Install the dependencies:

    go mod tidy

    Result:

    go: downloading github.com/aws/aws-sdk-go-v2 v1.36.3
go: downloading github.com/aws/aws-sdk-go-v2/service/sesv2 v1.42.0
...
go: downloading github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.6.34

  3. Run the application:

    go run main.go

    Result:

    DAEBWI6L7WN5.1RLCK********@ingress2-sas

Check the result

Make sure the recipient specified in the file named main.go in the Recipient field has received an email with the specified parameters.

How to delete the resources you created

To stop paying for the resources you created:

  • Delete the address.
  • Delete the DNS zone if you had created a resource record in it.
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