Postscale
Sign Up

Masked email addresses for your users

Generate unique, revocable aliases that forward to your users' real inboxes. Give them Apple-style Hide My Email functionality: embedded in your product, on your domain. Postscale Shield.

Get started free See Shield docs

Everything the product needs. Nothing it does not.

A focused API surface with production controls, predictable resources, and the operational visibility to run email confidently.

01

Unique aliases on demand

One API call, one new address. Alias-as-a-feature for signup flows, feedback forms, or any step where you'd rather not ask for a real email.

02

Forward to one or many

Each alias can forward to a single inbox or a team. Change the destination without breaking the alias. Disable with one call: the address stops forwarding, no deletion, no data loss.

03

Bring your own domain

Run aliases on shield.yourdomain.com so users see your brand, not ours. Shared shield.postscale.io is available for free-tier and quick starts.

04

SRS-correct forwarding

Sender Rewriting Scheme applied on every forward so SPF stays valid through the hop. Forwarded mail lands in inboxes, not spam.

05

Per-alias analytics

See which aliases are still receiving mail, which are silent, and which senders are hitting each. Revoke the noisy ones.

06

EU/EEA-hosted primary service data

Primary alias and forwarding service data is hosted in the EU/EEA. Standard DPA, documented subprocessors, and appropriate safeguards for limited infrastructure metadata.

Start with one request.

The public API uses explicit resources and familiar JSON. Move from a first request to production without changing integration models.

See Shield docs
cURL: create a masked alias ready
curl -X POST https://api.postscale.io/v1/shield/aliases \
  -H "Authorization: Bearer ps_live_..." \
  -H "Content-Type: application/json" \
  -d '{
    "forward_to": ["user@example.com"],
    "description": "signup:newsletter"
  }'

# Response
{
  "alias": {
    "address": "xk7m9p",
    "domain": "shield.postscale.io",
    "full_address": "xk7m9p@shield.postscale.io",
    "forward_to": ["user@example.com"],
    "active": true,
    "created_at": "2026-04-16T12:00:00Z"
  }
}

Further reading

01

Why masked emails are the future of online privacy

The case for shipping masked addresses as a first-class product feature, not an afterthought.

Read more
02

EU-hosted email APIs: what GDPR actually requires

Privacy features don't matter if the processor leaks data across the Atlantic. Here's the GDPR lens.

Read more

Frequently asked questions

How is this different from Apple Hide My Email?

Apple's product is consumer-facing and only works from Apple devices. Postscale Shield is an API: embed masked addresses inside your own product, on your own domain, for all your users regardless of platform.

Do aliases cost money to keep active?

Free-tier accounts include a working volume of active aliases; paid plans scale up. Disabled aliases are free to retain: we keep them inert rather than deleting, so re-enabling is one call.

What about abuse and rate limits?

Per-alias and per-sender limits are configurable. Unusually high inbound volume on a single alias fires a webhook so you can disable it before it damages deliverability.

Can I use my own domain for aliases?

Yes. Add an MX record and a couple of DNS entries, verify ownership, and aliases will run on shield.yourdomain.com instead of the shared subdomain.

Build the email workflow your product needs.

The free tier includes everything required to evaluate the API. No credit card required.

Create a free account