# Subscription inboxes (/docs/guides/subscription-inboxes)



A subscription inbox gives you a private eReader Relay address for newsletters. Messages are
collected first; they are not forwarded to a device the moment they arrive.

## Create an inbox [#create-an-inbox]

1. Open **Subscription inboxes**.
2. Select **Create subscription inbox**.
3. Give it a label that helps you recognize its purpose.
4. Decide whether to enable automatic confirmation.
5. Copy the private address after saving.

Automatic confirmation applies only to recognized publication platforms. Keep it off when you want
to review confirmation messages yourself or do not trust the sender.

> **Screenshot to add — Subscription inbox:** Capture the creation form and its automatic-confirm
> explanation. Never publish a real private subscription address.

## Subscribe to a newsletter [#subscribe-to-a-newsletter]

Use the private Relay address in the publisher's newsletter form. Complete any required confirmation.
After the first message is received, its sender appears as an observed newsletter and can be selected
when creating or editing a reading list.

## How newsletter content is used [#how-newsletter-content-is-used]

eReader Relay parses the received email and sanitizes its HTML before using it as an EPUB chapter.
Scripts, forms, tracking elements, and unsafe markup do not run. Supported inline images are kept
where possible.

The email body is the chapter. Ordinary file attachments are not parsed, converted, or added to the
EPUB. This includes PDFs, Word documents, calendar files, archives, audio, video, and images attached
as downloads. A supported raster image can be included only when the newsletter HTML explicitly
references it as an inline image and it passes the image safety limits.

Inbound email larger than 5 MB is rejected. Attachments count toward that message size even though
ordinary attachments are not included in the resulting EPUB.

## Keep the address private [#keep-the-address-private]

Treat a subscription inbox address as a secret routing address. Do not post it publicly. If it starts
receiving unwanted email, stop using it and create a replacement.

For missing confirmations or messages, see [Newsletter troubleshooting](/docs/troubleshooting/newsletters).