---
name: "rcpt500"
section: "8"
platform: "linux"
package: "ldap-gateways"
version: "2.0.23-6.3"
release: "Debian 3.0 (Woody)"
platforms: ["linux"]
url: "https://new.carta.tech/rcpt500"
---

# rcpt500(8)

mail to X.500 gateway program

## NAME

rcpt500 - mail to X.500 gateway program

## SYNOPSIS

**/usr/sbin/rcpt500 \[-l\] \[-h ldaphost\] \[-p ldapport\]** **\[-b searchbase\] \[-a\] \[-U\] \[-z sizelimit\] \[-u dapuser\]** **\[-f filterfile\] \[-t templatefile\] \[-c rdncount\]**

## DESCRIPTION

**rcpt500** is a mail-query server that answers X.500 white pages queries.  It is designed to be run out of your mail system alias file (or the equivalent). **rcpt500** accepts the entire contents (including headers) of an RFC 822 message on standard input.  The message is parsed, and a search or help command found in the Subject: header of message body is recognized and a reply is sent to the sender.

If you are using [**sendmail**(8)](/sendmail/8.md), you could add the following line to the [**aliases**(5)](/aliases/5.md) file (**/etc/aliases**) to have **rcpt500** invoked whenever mail is sent to the address *namelookup* on your host:

```

```

`    namelookup:	"|/usr/sbin/rcpt500 -l"`

## OPTIONS

- **-l**

  Enable logging of requests to the LOG\_DAEMON facility.

- **-h** *ldaphost*

  Specify an alternate host on which the ldap server is running.

- **-p** *ldapport*

  Specify and alternate TCP port where the ldap server is running.

- **-b** *searchbase*

  Specify an alternate base for searches.  *searchbase* should be a string-represented LDAP Distinguished Name.

- **-a**

  Turn off dereferencing of aliases for the LDAP search.

- **-U**

  Use Connectionless LDAP (over UDP).  This option is only available when **rcpt500** is compiled with -DCLDAP.

- **-z** *sizelimit*

  Limit the maximum number of entries returned to *sizelimit* entries.

- **-t** *templatefile*

  Specify an alternate template configuration file for use with the [**ldap\_init\_templates**(3)](/ldap_init_templates/3.md) facility, used by rcpt500.

- **-c** *rdncount*

  Specify the number of DN components to show for the names and DN attributes within entries matching the search.

## NOTES

The default values for most of the things you can specify with options are configured at compile time in the **include/ldapconfig.h.edit** include file.  Also included there are the pathname of the help file, the name of the command used to send replies, etc.  You should configure **ldapconfig.h.edit** for your site.

## FILES

- **/usr/share/ldap/rcpt500.help**

  help file

## SEE ALSO

[**ldap**(3)](/ldap/3.md), [**aliases**(5)](/aliases/5.md), [**sendmail**(8)](/sendmail/8.md)

## ACKNOWLEDGEMENTS

**OpenLDAP** is developed and maintained by The OpenLDAP Project (http://www.openldap.org/). **OpenLDAP** is derived from University of Michigan LDAP 3.3 Release.