---
title: "New SDKs for .NET, Rust, Elixir and Symfony"
description: "Working with .NET, Rust, Elixir or Symfony? Our new official SDKs make it easy to send email from your application."
url: "https://lettermint.co/changelog/new-sdks-for-dotnet-rust-elixir-and-symfony"
published: "2026-09-23"
last_updated: "2026-09-23"
---

# New SDKs for .NET, Rust, Elixir and Symfony

> Working with .NET, Rust, Elixir or Symfony? Our new official SDKs make it easy to send email from your application.

Building with .NET, Rust, Elixir or Symfony? You can now connect
Lettermint to your application with an official SDK. Install it and
you're sending [transactional emails](https://lettermint.co/features/transactional-emails)
and [broadcast emails](https://lettermint.co/features/broadcast-emails) with just a few
lines of code.

You may already know the community packages for .NET, Elixir and
Symfony. Those still work fine. The difference is that we maintain the
official SDKs ourselves, so every new Lettermint feature lands in them
too.

## Send email with .NET and C#

The .NET SDK is available on NuGet and requires .NET 8 or newer. Make
sure you pick `Lettermint`. The community SDK by
[ExciteOrg](https://github.com/ExciteOrg/lettermint-dotnet) goes by
`LettermintDotNet`.

Sending your first email looks like this:

```csharp
using Lettermint;

using var email = LettermintClient.Email("lm_project_token");

var response = await email
    .From("sender@acme.com")
    .To("recipient@acme.com")
    .Subject("Hello from Lettermint")
    .Html("<p>Hello World!</p>")
    .SendAsync();
```

Attachments and the Team API are covered in the
[.NET guide](https://lettermint.co/docs/guides/send-email-with-dotnet).

## The Rust SDK is now official

[Franz Geffke](https://github.com/franzos) wrote the first version of
the Rust SDK. We've since taken over maintenance and shipped version
1.0, which now works like the rest of our SDKs. The crate is still
called `lettermint` on crates.io. You'll need Rust 1.98 or newer and an
async runtime like Tokio.

Here's what sending an email looks like in 1.0:

```rust
use lettermint::Lettermint;

#[tokio::main]
async fn main() -> lettermint::Result<()> {
    let email = Lettermint::email("lm_project_token")?;

    email
        .email()
        .from("sender@acme.com")
        .to("recipient@acme.com")
        .subject("Hello from Lettermint")
        .html("<p>Hello World!</p>")
        .send()
        .await?;

    Ok(())
}
```

Already on the Rust SDK? If your `Cargo.toml` pins
`lettermint = "0.3"`, nothing changes for you. Before you upgrade to
1.0, check the
[migration guide](https://github.com/lettermint/lettermint-rust/blob/main/MIGRATING.md).
The [Rust guide](https://lettermint.co/docs/guides/send-email-with-rust)
has all the options.

## Transactional emails from Elixir and Phoenix

The Elixir SDK is on Hex and supports Elixir 1.15 and up. It works in
any Mix project, Phoenix apps included. You build an email one step at
a time:

```elixir
alias Lettermint.EmailBuilder, as: Email

client = Lettermint.email("lm_project_token")

client
|> Email.new()
|> Email.from("sender@acme.com")
|> Email.to(["recipient@acme.com"])
|> Email.subject("Hello from Lettermint")
|> Email.html("<p>Hello World!</p>")
|> Email.send()
```

If you send mail through Swoosh, keep using the
[Lettermint adapter](https://hexdocs.pm/swoosh/Swoosh.Adapters.Lettermint.html).
The SDK doesn't replace it. Add the SDK when you also want to call the
Team API or verify webhooks. You'll find more examples in the
[Elixir guide](https://lettermint.co/docs/guides/send-email-with-elixir).

## Connect Lettermint to Symfony Mailer

For Symfony Mailer, install `lettermint/symfony-mailer` with Composer.
It needs PHP 8.2 and Symfony Mailer 6.4, 7.4 or 8. A community
integration by
[somehow digital](https://github.com/somehow-digital/symfony-lettermint-mailer)
already existed, and you can keep using it.

After installing, register the integration once in
`config/services.yaml` and add your project API token to the DSN:

```text simple
MAILER_DSN=lettermint+api://lm_project_token@default
```

That's it. You keep sending email through `MailerInterface` like you
always did, without changing your code. Emails you queue with Symfony
Messenger go through Lettermint as well. The
[Symfony guide](https://lettermint.co/docs/guides/send-email-with-symfony)
walks you through the registration step.

## All official SDKs at a glance

The .NET, Rust and Elixir SDKs do more than send email. You can also
use them to manage domains and projects through the
[Team API](https://lettermint.co/changelog/team-api-now-available-in-our-sdks) and to verify
webhook signatures.

That brings our official SDKs and integrations to Node.js, Nuxt, PHP,
Laravel, Symfony, Python, Go, Java, .NET, Elixir and Rust. Every email
you send with them is processed in the EU. You can find them all on
our [integrations page](https://lettermint.co/integrations).