Are you cleaning your email lists on a regular basis? Verifying your email list before launching a campaign is the single most important action in email marketing.All those hours spent on writing emails, designing templates mean nothing if your emails fail get delivered. Hard bounces and non-valid emails in your list kills your deliverability. Having just 1% bad emails in the list can reduce deliverability by 10%. In the worst-case scenario, you can get blacklisted permanently.