The short answer is no. Some databases are opt-in compliant lists, and in these cases this information is clearly indicated as such. While some databases have contact information such as email address, this information is part of the database for reference information.
By purchasing this database you are not purchasing any rights or warranties to contact using such supplied information. Any and all applicable governing laws for SPAM/etc still apply. In general, our databases are not meant as 'email contact' or electronic communication lists. Our lists are supplied from brokers using direct sign-up and public information resources. No attempt is made to validate or or otherwise check the accuracy of provided email addresses.
Working contact or communication using the provided email address should not be a deciding factor in making a purchase decision, these are not meant to be sold or used as 'Email Lists'.