openldap add mail attribute to users - ldap

Question

I'm trying to add 'mail' attribute to users on my openldap server but somehow it fails.
I tried using ldapmodify but I get this:
ldap_modify: Object class violation (65)
additional info: attribute 'mail' not allowed
Here's how my schema looks like:
# LDIF Export for ou=users,dc=mydomain,dc=com
# Server: (ldap.mydomain.com)
# Search Scope: sub
# Search Filter: (objectClass=*)
# Total Entries: 63
version: 1
# Entry 1: ou=users,dc=mydomain,dc=com
dn: ou=users,dc=mydomain,dc=com
objectclass: organizationalUnit
objectclass: top
ou: users
# Entry 2: uid=tom.hanks,ou=users,dc=mydomain,dc=com
dn: uid=tom.hanks,ou=users,dc=mydomain,dc=com
cn: tom.hanks
description: User account
gecos: tom.hanks
gidnumber: 100
homedirectory: /home/tom.hanks
loginshell: /bin/bash
objectclass: account
objectclass: posixAccount
uid: tom.hanks
uidnumber: 1005
userpassword: blahblah

Answer 1

Include objectclass: iNetOrgPerson to add the mail attribute.

Answer 2

In order to give the user the Attribute mail you first have to add the mail attribute to the user's olcObjectClasses.
This can be done by a modification via an ldif like this:
dn: cn={12345}someName,cn=schema,cn=config
changetype: modify
delete: olcObjectClasses
olcObjectClasses: {1}
-
add: olcObjectClasses
olcObjectClasses: {1}( 1.3.6.1.4.1.12344556.1.1.1 NAME 'yourObjectClassEGAccount' DESC 'some description' SUP inetOrgPerson STRUCTURAL MUST ( requiredparam1 $ requiredParam2 $ reqParam3 ) MAY ( optionalParam1 $ optionalParam2 ) ) )
-
See the documentation for ldapmodify for details: Oracle ldapmodify Doc
The modification is then given to ldap via the following command (command line):
sudo ldapmodify -f filename.ldif
make sure to read the documentation on whether you need further parameters like eg. -h for hostname or -Y for a proxyDN: lmodify Doc