Elastic Email Rust SDK

The official Rust client library for the Elastic Email REST API v4.

Installation • Quick start • Examples • API reference • Models • Contributing

Features

• Transactional and bulk email. Send single messages, bulk campaigns or CSV merge-file sends.
• Contacts, lists and segments. Add, update, import, export and bulk-delete contacts.
• Campaigns and automations. Create, update, pause and trigger automations for a contact.
• Templates, files and attachments. Manage templates and uploaded files.
• Domains. Verify sending domains and check SPF, DKIM, tracking and certificate status.
• Webhooks and inbound routes. Receive delivery events and route incoming mail.
• Statistics, events and suppressions. Track delivery, bounces, complaints and unsubscribes.
• Subaccounts and security. Manage subaccounts and API keys.
• Async. Every endpoint is an async fn built on reqwest, with typed models powered by serde.

Requirements

You'll also need an Elastic Email API key. You can create one in your API settings. Each endpoint's documentation lists the access level it needs.

Installation

The crate isn't published on crates.io. Add it as a Git dependency pinned to a release tag:

cargo add ElasticEmail --git https://github.com/ElasticEmail/elasticemail-rust --tag 4.2.0
cargo add tokio --features macros,rt-multi-thread

Or add it to your Cargo.toml:

[dependencies]
ElasticEmail = { git = "https://github.com/ElasticEmail/elasticemail-rust", tag = "4.2.0" }
tokio = { version = "1", features = ["macros", "rt-multi-thread"] }

Cargo pulls in the SDK's dependencies (reqwest, serde, serde_json, serde_with, serde_repr, url and uuid) for you.

Quick start

Configure the client

use ElasticEmail::apis::configuration::{ApiKey, Configuration};

let config = Configuration {
    api_key: Some(ApiKey {
        prefix: None,
        key: std::env::var("ELASTICEMAIL_API_KEY")?,
    }),
    ..Default::default() // base_path defaults to https://api.elasticemail.com/v4
};

[!TIP] Keep your API key out of source code. Load it from an environment variable, a .env file (e.g. with dotenvy) or a secrets manager.

Send a transactional email

use ElasticEmail::apis::{emails_api, Error};
use ElasticEmail::models::{
    BodyContentType, BodyPart, EmailContent, EmailTransactionalMessageData, TransactionalRecipient,
};

let content = EmailContent {
    subject: Some("Welcome aboard!".to_string()),
    body: Some(vec![
        BodyPart {
            content: Some("<h1>Hello!</h1><p>Thanks for signing up.</p>".to_string()),
            ..BodyPart::new(BodyContentType::Html)
        },
        BodyPart {
            content: Some("Hello! Thanks for signing up.".to_string()),
            ..BodyPart::new(BodyContentType::PlainText)
        },
    ]),
    ..EmailContent::new("My App <no-reply@yourdomain.com>".to_string())
};

let message = EmailTransactionalMessageData::new(
    TransactionalRecipient::new(vec!["john.doe@example.com".to_string()]),
    content,
);

match emails_api::emails_transactional_post(&config, message).await {
    Ok(result) => println!(
        "Sent. TransactionID: {}, MessageID: {}",
        result.transaction_id.unwrap_or_default(),
        result.message_id.unwrap_or_default()
    ),
    Err(Error::ResponseError(e)) => {
        eprintln!("Elastic Email API error {}: {}", e.status.as_u16(), e.content)
    }
    Err(e) => eprintln!("Request failed: {e}"),
}

The from address must use a domain you've verified in your Elastic Email account.

Send from a template with merge fields

use std::collections::HashMap;

let content = EmailContent {
    template_name: Some("welcome-template".to_string()),
    merge: Some(HashMap::from([("firstname".to_string(), "John".to_string())])),
    ..EmailContent::new("My App <no-reply@yourdomain.com>".to_string())
};

let message = EmailTransactionalMessageData::new(
    TransactionalRecipient::new(vec!["john.doe@example.com".to_string()]),
    content,
);

emails_api::emails_transactional_post(&config, message).await?;

Using a proxy or custom timeout

Configuration.client is a regular reqwest::Client, so you can configure proxies, timeouts and TLS with the reqwest builder (add reqwest = "0.12" to your dependencies):

use std::time::Duration;

let client = reqwest::Client::builder()
    .proxy(reqwest::Proxy::all("http://myProxyUrl:80/")?)
    .timeout(Duration::from_secs(600))
    .build()?;

let config = Configuration { client, ..config };

More examples

More complete, runnable samples are in the Elastic Email examples repository. It covers transactional email, SMTP, webhooks, inbound email, contacts and serverless platforms across 20+ languages and frameworks.

• 🦀 Rust examples (standalone Tokio binaries and an Axum app)
• 📂 All examples

Authentication

API limits

• Up to 20 concurrent connections per account
• A hard timeout of 600 seconds per request

API reference

All URIs are relative to https://api.elasticemail.com/v4. The SDK covers 114 endpoints across 16 API modules: campaigns_api, contacts_api, domains_api, emails_api, events_api, files_api, inbound_route_api, lists_api, security_api, segments_api, statistics_api, sub_accounts_api, suppressions_api, templates_api, verifications_api and webhook_api. Each endpoint is a free async fn in ElasticEmail::apis::<module> that takes &Configuration as its first argument.

All URIs are relative to https://api.elasticemail.com/v4

Models

• AccessLevel
• AccountStatusEnum
• ApiKey
• ApiKeyPayload
• BodyContentType
• BodyPart
• Campaign
• CampaignOptions
• CampaignRecipient
• CampaignStatus
• CampaignTemplate
• CertificateValidationStatus
• ChannelLogStatusSummary
• CompressionFormat
• ConsentData
• ConsentTracking
• Contact
• ContactActivity
• ContactPayload
• ContactSource
• ContactStatus
• ContactUpdatePayload
• ContactsList
• DeliveryOptimizationType
• DkimRecord
• DomainData
• DomainDetail
• DomainOwner
• DomainPayload
• DomainUpdatePayload
• EmailContent
• EmailData
• EmailJobFailedStatus
• EmailJobStatus
• EmailMessageData
• EmailPredictedValidationStatus
• EmailRecipient
• EmailSend
• EmailStatus
• EmailTransactionalMessageData
• EmailValidationResult
• EmailValidationStatus
• EmailView
• EmailsPayload
• EncodingType
• EventType
• EventsOrderBy
• ExportFileFormats
• ExportLink
• ExportStatus
• FileInfo
• FilePayload
• FileUploadResult
• InboundPayload
• InboundRoute
• InboundRouteActionType
• InboundRouteFilterType
• ListPayload
• ListUpdatePayload
• LogJobStatus
• LogStatusSummary
• MergeEmailPayload
• MessageAttachment
• MessageCategory
• MessageCategoryEnum
• NewApiKey
• NewSmtpCredentials
• Options
• RecipientEvent
• Segment
• SegmentPayload
• SmtpCredentials
• SmtpCredentialsPayload
• SortOrderItem
• SplitOptimizationType
• SplitOptions
• SubAccountInfo
• SubaccountEmailCreditsPayload
• SubaccountEmailSettings
• SubaccountEmailSettingsPayload
• SubaccountPayload
• SubaccountSettingsInfo
• SubaccountSettingsInfoPayload
• Suppression
• Template
• TemplatePayload
• TemplateScope
• TemplateType
• TrackingType
• TrackingValidationStatus
• TransactionalRecipient
• Utm
• VerificationFileResult
• VerificationFileResultDetails
• VerificationStatus
• Webhook
• WebhookCreatePayload
• WebhookUpdatePayload

Known issues

• File uploads through multipart form data aren't implemented by the generator yet. The file argument is ignored by contacts_import_post, suppressions_bounces_import_post, suppressions_complaints_import_post, suppressions_unsubscribes_import_post and verifications_files_post. For contact imports, pass a file_url instead. For the other endpoints, send the multipart request with reqwest directly for now.

Documentation

Every API module and model has a Markdown page in docs/. To browse the generated Rust API docs locally, run:

cargo doc --open

Versioning

The SDK follows the Elastic Email API v4. Each release is a Git tag. Versions and release notes are listed in GitHub Releases. Pin the tag in your Cargo.toml to the version you want.

• API version: 4.0.0
• SDK version: 4.2.0
• Generator version: 7.11.0
• Build package: org.openapitools.codegen.languages.RustClientCodegen

Contributing

Contributions are welcome! Most of this SDK is generated from the Elastic Email OpenAPI specification, so please read CONTRIBUTING.md before opening a pull request.

• 🐛 Report a bug
• 💡 Request a feature
• 🔒 Report a security issue

This project follows the Contributor Covenant Code of Conduct.

Support

[!IMPORTANT] The fastest way to get help is the chat widget on elasticemail.com. Our support team can help with your account, sending, deliverability and API questions.

• 💬 Chat with support on elasticemail.com (preferred)
• 📚 API documentation
• 🧪 Examples repository
• 🐛 GitHub issues, for bugs in this SDK only

License

Released under the MIT License. Copyright © 2021–2026 Elastic Email.