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

# How the sender shows

> How Faxbeep shows the sender of a test: a masked number, a masked address, a station ID or Unknown.

Each test shows its sender on its card in the grid, in the title of its page, and in the title of its group page. Faxbeep masks the sender before it shows it.

## Where the sender comes from

* **Fax by phone.** The sender is what reaches Faxbeep with the call: the phone number of the line, or the <Tooltip headline="Station ID (TSID)" tip="The name or number that a fax machine sends to say who it is. Many machines print it at the top of each page." cta="Glossary" href="/reference/glossary#station-id">station ID</Tooltip> of the machine. Many faxes arrive with no sender at all.
* **Test by email.** The sender is the address in the From line of the email, in lower case.

## The rules

The first rule that fits applies:

1. "Unknown" stays "Unknown".
2. An email address keeps the first character of the name, the first character of the domain, and the last part of the domain. The rest becomes `***`.
3. A value that already holds a `*` shows as it is.
4. A value with fewer than 6 digits shows as it is.
5. A value with 6 or more digits loses its middle 5 digits: each one becomes `*`. Letters, spaces, `+` and `-` stay where they are.

## Examples

The numbers and addresses below are made up.

| What was sent | What the site shows | Rule |
| - | - | - |
| `+15555550123` | `+155*****123` | Phone number: the middle 5 digits are masked |
| `+1 555-555-0123` | `+1 55*-***-*123` | Spaces and hyphens stay; 5 digits are masked |
| `scanner@example.com` | `s***@e***.com` | Email address |
| `Copier.3F@mail.example.co.uk` | `c***@m***.uk` | Email address: lower case, last part of domain |
| `FrontDesk` | `FrontDesk` | Station ID with no digits: not masked |
| `Room204` | `Room204` | Station ID with fewer than 6 digits: not masked |
| `Office5555550123` | `Office555*****23` | Station ID with 6 or more digits: digits masked |
| `+1555***0123` | `+1555***0123` | Already masked: shown as it arrived |
| No sender | `Unknown` | Unknown |

## What masking does not hide

<Warning>
  The mask covers the sender that Faxbeep shows. It does not cover the page itself. Many fax machines print their station ID and their number at the top of each page, and that line is part of the image. Faxbeep does not mask it. Check the header of your machine before you send a test.
</Warning>

* For a test by email, Faxbeep never shows the subject or the message text of the email.
* Faxbeep keeps the full sender. It uses it to put similar tests from one sender together. See [Groups](/results/groups).


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