Open LDAP 2.4 - Adding new schema and enabling existing schema

By default OpenLDAP having the core schema only. When adding entities to the LDAP database following structural schemas are very important and required. These schemas and related ldif files are already available at /etc/openldap/schema folder but may not be enabled. Following commands can be used to enable required schemas

ldapadd -Q -Y EXTERNAL -H ldapi:/// -f cosine.ldif 
ldapadd -Q -Y EXTERNAL -H ldapi:/// -f nis.ldif

When LDAP is used as the authentication method of postfix or Dovecot, postfix schema is required (http://www.postfix.org/LDAP_README.html) but that is not shipped with OpenLDAP by default. You may need to download the schema from following URI (https://github.com/credativ/postfix-ldap-schema)

In any case if the URL is not available, I have given the data in the postfix schema

attributetype (

1.3.6.1.4.1.4203.666.1.200

NAME 'mailacceptinggeneralid'

DESC 'Postfix mail local address alias attribute'

EQUALITY caseIgnoreMatch

SUBSTR caseIgnoreSubstringsMatch

SYNTAX 1.3.6.1.4.1.1466.115.121.1.15{1024}

)

attributetype (

1.3.6.1.4.1.4203.666.1.201

NAME 'maildrop'

DESC 'Postfix mail final destination attribute'

EQUALITY caseIgnoreMatch

SUBSTR caseIgnoreSubstringsMatch

SYNTAX 1.3.6.1.4.1.1466.115.121.1.15{1024}

)

objectclass (

1.3.6.1.4.1.4203.666.1.100

NAME 'postfixUser'

DESC 'Postfix mail user class'

SUP top

AUXILIARY

MAY (

mailacceptinggeneralid $ maildrop

)

)

# Schema as required by Postfix: http://www.postfix.org/LDAP_README.html

You need to download this schema and place it in /tmp folder as you need to create the ldif file to integrate to the LDAP server. Good tutorial is available at https://www.youtube.com/watch?v=qAedVMMunk8 which describes how to enable a new schema for LDAP 2.4

References:
https://www.youtube.com/watch?v=qAedVMMunk8 - tutorial video
https://github.com/credativ/postfix-ldap-schema - Github postfix schema