[Dovecot] %s service variable substitution

I'm using 1.0rc15. We switched over to using deliver LDA and using dovecot's sasl implementation for postfix...

In our ldap configuration we were using (similar for password filter)

user_filter = (&(objectClass=mailUser)(mail=%u)(mailSettingValue=%s))

The problem is these new services, namely deliver and postfix, are accessing the authentication mechanisms and I am not sure what to put in ldap so the %s can match.

Each user currently only has a mailSettingValue=IMAP. This can be expanded for multiple entries.

Thanks,

Jim