LDAP schema issue

Hi

This is the current relevant part of my schema:

attributetype ( objectClassAccount:1.1 NAME 'mailAddress' DESC 'The hosted mail addresses' EQUALITY caseIgnoreIA5Match SUBSTR caseIgnoreIA5SubstringsMatch SYNTAX 1.3.6.1.4.1.1466.115.121.1.26{256} SINGLE-VALUE )

1. How can I achieve, that upper case will always and only be stored as lower case? 2. How do I achieve a validation check whether the value is actually a valid email addres - very simple: user@domain.tld?

Thanks & Best regards Leander