---
name: "mkalias"
section: "8"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/mkalias/8"
---

# mkalias(8)

a YP map conversion program

## NAME

**mkalias** – a YP map conversion program

## SYNOPSIS

**mkalias** \[**-nv**\]\[ **-E** \| **-e** \[**-du**\]\] *input* \[*output*\]

## DESCRIPTION

**mkalias** is used to convert a mail.aliases map to a mail.byaddr map. This is an inverse map of user@host (or user!host) back to alias.

The options are as follows:

- **-d**

  Assume domain names are OK. Only useful together with **-E** or **-e**.

- **-E**

  Same as **-e**, but also check for any MX-record.

- **-e**

  Check host to verify that it exists.

- **-n**

  Capitalize name. e.g., mats.o.jansson becomes Mats.O.Jansson.

- **-u**

  Assume UUCP names are OK. Only useful together with **-E** or **-e**.

- **-v**

  Verbose mode.

- *input*

  Use this map as input.

- *output*

  Use this map as output. If the output map isn't given, don't create database. Can be useful together with **-E** or **-e**.

## SEE ALSO

[yp(8)](/yp/8.md), [ypserv(8)](/ypserv/8.md)

## AUTHORS

Mats O Jansson ⟨*moj@stacken.kth.se*⟩

## BUGS

**mkalias** on SunOS 4.1.x seems to have a **-s**. Since I don't know what it is supposed to do, I haven't implemented it. But it is accepted by the program.