To find out more about MailKing by cloudHQ, click here.
To install MailKing: Email Campaigns in Gmail by cloudHQ chrome extension, click here.
To install Export Email to Google Sheets Google Workspace Add-on, click here.
To start wizard to create a campaign click here.

Here are the steps explaining how to create and send an email campaigns:

  1. Create spreadsheet with email addresses and merge tagsAn example spreadsheet can be found here.
  2. Load the spreadsheet by clicking on Import from Google Spreadsheet
  3. Write an email
  4. Send or schedule the campaign