The People Picker allows us to select users from the company directory. But the
People Picker control in InfoPath 2010 has two important limitations. First, it
does not query for the user’s email. Second, its schema is locked. This means
that we cannot add an additional node (to store the email), nor rules. This is
problematic for sending emails: a data connection which submits the form via
email requires an email address for the recipient. This document will explain a
workaround to this scenario.