The best way is to follow up by phone as soon as possible. You can get connected with the contact directly and follow one of the Voice Scripts to talk to a GateKeeper or a Decision Maker. 

If you have an appointment setter, they can follow up for you and set up an appointment for you to close the sale. 

If you tried reaching out to the contact by phone but didn't get through, leave a voicemail, then follow up with an email and make sure to call again within the next 24 hours.

Related Articles

Can I Send the Lead Gen Campaign to a Cold Lead
Should I Re-Write the Emails for the Lead Gen Campaign
How Would I Know That the Lead Saw the Emails I Sent Them
How Soon Should I Follow up With a Lead