There are two metrics you need to look out for – quality and coverage. You might hear a lot of hype about Best Database providers and real-time machine processing but human verification is the key to the highest data quality.
As for the coverage, the more the better. But honestly, no database in the world can possibly have all the data you need. There will always be gaps – be it on the department level of enterprises of missing SMBs. So you need a database provider who along with providing access to their existing database, also offers custom research services.
Taking all of that into account, SalesIntel remains the best email database provider that guarantees at least 95% accuracy. Along with having 100% coverage on 8M+ companies, it also offers Research-on-demand service where customers can simply request the email addresses of specific accounts they can’t find in the database.