# WHATPORT(1038)

## NAME

port 1038 — MTQP (Message Tracking Query Protocol) — MTQP, the standards-track protocol for asking a mail server what happened to a message — specified, but barely deployed.

Protocol: TCP/UDP  
IANA registry

## DESCRIPTION

MTQP is defined in RFC 3887 (Standards Track, 2004) and uses TCP 1038. It is a line-oriented text protocol in the style of POP3 and NNTP: a client presents an envelope identifier plus a secret from the SMTP submission, and the server returns the message's tracking history as a MIME body. It was designed to pair with the SMTP message-tracking extension, but almost no mail platform shipped it, so a listener on 1038 in the wild is far more likely to be an unrelated application or a legacy Windows RPC endpoint than a real MTQP server.

## EXPOSURE

**Expose with care.** MTQP hands out message routing history to anyone holding the envelope ID and secret, and RFC 3887 expects TLS and authentication; a genuine MTQP server should not sit unprotected on a public IP.

## CHECK

```sh
nc -v TARGET 1038
```

## SEE ALSO

- spec — [RFC 3887 — Message Tracking Query Protocol](https://www.rfc-editor.org/rfc/rfc3887.html) (rfc-editor.org)
- iana — [IANA Service Name and Transport Protocol Port Number Registry](https://www.iana.org/assignments/service-names-port-numbers/service-names-port-numbers.xhtml) (iana.org)

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HTML: <https://whatport.net/1038/> · JSON: <https://whatport.net/1038.json> · full dataset: <https://whatport.net/ports.json>