# Regions and data residency

Two sending regions, an EU default, storage in the EU either way, and no way to pick one today.

There are two regions, us and eu. The default is eu. This page says what that actually changes, which is less than the word suggests, and it is honest about the fact that you cannot choose today.

The region of an existing address is not changeable, and there is no field on a send and no setting in the dashboard that moves one. It is resolved from the sending domain, then the workspace, then the default, and it reads back on GET /v1/ips as default_region and as region on each address. The one place you choose is POST /v1/ips, which takes an optional region for the address it is about to assign; omit it and the workspace default is used.

### What changes

One thing: which SES endpoint the message is handed to, us-east-1 or eu-west-1. That is the physical point at which your mail leaves for the recipient's server.

Storage is in the EU in both cases. Message bodies, delivery events, contacts, and everything else this API returns live in the EU whichever region sent the mail. So a workspace on the us region is not a workspace whose data is in the United States, and it would be wrong to tell an auditor that it is.

The residency block on GET /v1/ips:
```json
{
  "default_region": "eu",
  "residency": { "sending": "eu-west-1", "storage": "eu", "compute": "eu" }
}
```

### How it is decided

In order, and the first answer wins: the sending domain, then the workspace, then eu. So a domain that carries a region uses it, and everything else falls through to the workspace setting, and a workspace with nothing set is on eu.

### Does it matter for deliverability

Much less than people expect. Receiving servers judge a message on its authentication, its sending reputation, and its content. Geographic proximity between the sending server and the receiving one affects latency by milliseconds and affects filtering by essentially nothing.

What does matter is on other pages: verify the domain including all three DKIM records, publish DMARC, send a real text part, and warm up rather than moving your whole volume in one day. See /docs/domains and /docs/troubleshooting.

### What to tell a compliance reviewer

- **Where is data stored**: The EU, for every workspace, regardless of sending region.
- **Where does processing happen**: The EU.
- **Where does mail leave from**: eu-west-1 by default, us-east-1 for a workspace or domain on the us region.
- **Can we require a region**: Not through the API today. Ask us at https://emails.sh/contact and it is set for you.
- **How do we verify what ours is**: GET /v1/ips returns default_region and the residency block above. That is the authoritative answer, and it is readable with any key holding the workspace scope.

Retention is separate from residency and is the same in both regions: message bodies for 30 days, delivery events for 12 months. See /docs/delivery.

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Base URL: https://emails.sh/v1. Auth: `Authorization: Bearer esh_...`.
Whole API in one file: https://emails.sh/llms.txt. All documentation: https://emails.sh/docs.md.