> ## Documentation Index
> Fetch the complete documentation index at: https://dugble.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Choosing a Region

> Choose a supported sending region and TLS mode for your Dugble sender domain.

Sender domains are provisioned in a specific sending region. Choose the region when you create the domain; the region determines where Dugble provisions the underlying email sending infrastructure for that domain.

## Supported regions

Dugble currently supports these sender-domain regions:

| Region       | Location              |
| ------------ | --------------------- |
| `us-east-1`  | US East (N. Virginia) |
| `eu-north-1` | Europe (Stockholm)    |

Requests using another region are rejected as unsupported.

## TLS mode

When creating a sender domain, you can also set `tls` to one of:

* `opportunistic` — the default when `tls` is omitted.
* `enforced` — records an enforced TLS preference for the sender domain.

```json theme={null}
{
  "name": "mail.example.com",
  "region": "eu-north-1",
  "tls": "enforced"
}
```

<Note>
  The domain API accepts only `name`, `region`, and optional `tls` as sender-domain configuration. Tracking options, receiving capabilities, and custom return-path configuration are not customer-configurable domain fields.
</Note>

<Tip>
  Choose the region closest to your operational requirements and keep the same region when recreating or transferring sender-domain infrastructure.
</Tip>