You can find email addresses in several resources:

• PitchBook – On the left-hand panel, under Screeners, select People. You can search contacts by name, firm, position, and other relevant fields.
• Capital IQ – On a Company’s page, under the Key Professionals box, click View All.
• Leadership Connect - Search by individual name, or look up specific government departments, companies, non-profits or other organizations.
• Nexis Dossier – From a company's profile, use the left-hand menu to open up Company Information. There are categories for Executive Contacts and Professional Contacts.