OK, we can talk about replacing the AuthenticationProvider with a subclass of LdapAuthenticationProvider etc. BUT, before going down that road...

The real problem here is that Robert@internal.ldap (ldap name) wants to log in as "Robert" and have LabKey send mail to "Bobby.Bobby@mail.com".

A sneaky operational way to do this is to have an SMTP server that is handles accepts mail using the LDAP name and forwards it to the correct email address.