Well, that's the problem.
The server software I use (more specific gerrit) uses the string in the database and performs a case sentitive compare

in order to authenticate the user when committing changes (you can only commit changes which include your email account).

Because "example@googlemail.com" is not "Example@googlemail.com" it fails.

You can add multiple email accounts. But this does not work as ldap stops you, because in it's opinion it already exists.
LDAP understands then "Example" == "example" and won't let you create it.

The gerrit devs (if I recall correctly) argued that this behavior is intentional as due to the standard, mails can be case sensitive and get to different recipients.

Now I'd like to know if it possible to modify the scheme that way so that mail works case sensitive (because that's also what the standard says).

Or if there is a way to force the creation of entries with the "same" value

Thanks in advantage.