discuss Which Useful( Worthy) tools for outbound marketing you are using?

[Awesome Decision]

Which is your favourite ( according to you worthy) tool for outbound marketing.?
Paid or unpaid?
My favourite -
1.Hunter.io and clearbit.( to find out executive email)
2.whois.com , whoxy.com, godaddy whois ( for domain whois data)
3.Google, linkedin and twitter ( for research and find out end users)
4.Mailtrack.io and streak for ( seen email open)

 

[Chinwong]

Thanks for everyone who contributed. I gained some tangible Information here. Will have to try them out.

BTW, hunter.io doesn't accept my Gmail and mail account for registration. Any help?

 

[Optimal Names]

rocketbolt, which I had suggested earlier, seems to have gone away, disappeared... It nowhere to be found. Seeking an alternative...

 

[dennisok]

Thanks for your contributions!