Note: you must set up your custom email domain first, such as ours which ends in @dripjobs.com
Email domains can be found for fairly cheap through godaddy.com or other vendors.
Follow the article above, but if you get stuck please be aware that we cannot help, so you may need to hire someone to help you.
Once this is set up:
Click on the megaphone, then in the popup you can write out your subject line and message. Click on the keywords to copy to your clipboard, and then paste them into the body of your email as desired. Keywords let the system know to fill in appropriate information, such as the customer's first name for {first-name}.
Click Send Blast.
If you prefer to email all your customers, you can export the data in order to do this. Click on Contacts on the left. The easiest way to do this (because of formatting) is to click Copy and paste the data into a google sheet. This will put the name, email, etc. in separate columns so you can easily use the data with your preferred email service.