How Tempx Temporary Email Works

This page explains what happens when you use Tempx, so you can decide whether it fits what you need.

1. An address is generated

When you open the Tempx inbox, Tempx creates a random address of the form abcd1234efgh@tempx.uk. The local part is drawn from a large random space, so nobody can guess your address or type it in by chance. The address is stored only in your browser, along with a signed token that lets your browser, and only your browser, read that inbox. The address never appears in a shareable URL.

2. Mail is delivered to Tempx

The tempx.uk domain is configured to route all incoming mail to a serverless function. When someone sends a message to your temporary address, that function receives the raw email directly from the sending mail server, there is no third-party mailbox in between.

3. The message is parsed and cleaned

The function parses the message and keeps only what is needed to display it: the sender, the subject, the date, the plain-text body and the HTML body. Before any HTML is shown to you it is sanitized: scripts, styles, iframes, forms and event handlers are removed, links are made safe, and remote images load only inside a locked-down, sandboxed frame (you can hide them per message). When you open a message it is rendered inside that frame as a second layer of protection.

4. Attachments are verified, not trusted

Attachments are handled defensively. The file type is determined from the file's actual content (magic bytes), never from the type the sender claims. Executable and script files, .exe, .dll, .js, .sh, .bat and similar, are refused outright. File names are sanitised. Only small verified images can be previewed; every other file, including PDFs and large files, can only be downloaded, forced by the server. Nothing is ever rendered or executed inline. Attachment files are stored temporarily in object storage with an expiry, accessed only through short-lived signed links that expire within minutes, and deleted automatically together with their message.

5. You read it in the inbox

Your browser polls for new mail every few seconds while the tab is open, and you can press Refresh Inbox at any time. Open a message to read it; delete individual messages or clear the whole inbox whenever you like.

6. Everything expires

Each message is scheduled for deletion when it arrives. Once the retention period passes (1 hour by default, and always shown in the app), the message is permanently removed by an automated job, including any attachment files, which carry the same expiry and are cleaned up by the same automated sweep. There is no archive and no way to recover a deleted message. If you generate a new address, the old inbox becomes unreachable from your browser and its messages expire on their normal schedule.

SMTP capture: testing your own outgoing mail

Tempx also runs an SMTP gateway, a second way a message can arrive. It exists for developers who are testing software that sends email: signup confirmations, password resets, transactional notifications. Instead of aiming those messages at a real mailbox (or a colleague), you aim them at Tempx.

Create SMTP credentials in your Tempx account, a username and a password that is shown exactly once. Then point your application's SMTP settings at smtp.tempx.uk on port 587 with STARTTLS; any language or framework with an SMTP client works. Authentication is validated live against Tempx, so the password is never stored on the gateway itself.

The gateway is a capture trap: every message is accepted and captured into the inbox paired with the credential, where it goes through the same parsing, sanitization and retention as any other message. The gateway never relays, nothing is ever forwarded to another mail server, so a misconfigured test run can never email a real person.

Limitations

• Receive-only. You cannot send or reply from a Tempx address.
• No delivery guarantee. Some senders block known disposable-email domains; if a site refuses tempx.uk, you will need a different address.
• Not for important accounts. Because mail is deleted fast and the service can change or pause at any time, never use Tempx where you might need the address again later.
• Not end-to-end private. Mail arrives over standard channels and is stored briefly in plain form so it can be displayed. Do not send secrets to a temporary address.

For data handling details, see the Privacy Policy. For acceptable use, see the Terms of Service.

Create a temporary email address

Open the inbox to generate a temporary address and receive your first message.

Go to your inbox