Send email marketing campaigns from inside your Gmail account and get the highest response rates you've ever seen. Even better, set follow-up emails to send automatically to non-responders.
It's really good product, and useful for email marketers and lead gen managers. So one question: How you validate(or verify) customer email list?
We're use Proofy.io (https://proofy.io/) service for this goal and same services like this.
So waiting for your reply ....
I suggest you to check validity of your email database before you start sending emails. For example you can use Email Verification Add-on https://emailverificationaddon.com for that.
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