Bouncing Leads from Lead Finder

The customer wanted to point out that the Leads database was very poor. They were getting bounces on 10% of the emails they sent. They didn't know how the verification was done, but it didn't seem to be effective. Their email reputation was suffering due to these bounced messages. They also stated that in own article, we had mentioned to avoid a database that gives more than 3% bounces. So, there was a need to investigate this issue, as the verification was not working, and they were still getting bounced emails. It was like one out of every ten they sent.