Email databases for school principals as well as other administrative staff of various schools and educational organizations are available. However, these databases are typically behind a paywall. They contain various types of information, such as the name of the school and principal in addition to the email.
The principals email list offered by Marketing Emaillist on its website, for example, is sold for just under $500 as of 2015. The list contains records of approximately 93,000 different school principals in the United States. MCH Data also offers a school and school district administrator database which contains approximately 71,909 principal email addresses.