You can check it here:

• https://cards-dev.twitter.com/validator
• https://developers.facebook.com/tools/debug/sharing/?q=mailhustle.com

Current code:

    <meta property="og:title" content="mailhustle.com - Gmail inbox and Facebook data dump actionable insights. #OwnYourData"/>
    <meta property="og:image" content="https://mailhustle.com/images/mailhustle-preview-square.jpg""/>
    og:site_name" content="mailhustle.com"/>
    og:description" content="Ethereum smart contract is live, leveraging power of the blockchain."/>

    twitter:card" content="summary_large_image">
    twitter:site" content="@mailhustle">
    twitter:creator" content="@mailhustle">
    twitter:title" content="mailhustle.com - Gmail inbox and Facebook data dump actionable insights. #OwnYourData">
    <meta name="twitter:description" content="Ethereum smart contract is live, leveraging power of the blockchain.">
    <meta name="twitter:image" content="https://mailhustle.com/images/mailhustle-preview-square.jpg">   

How it looks in practice:

Preview text is too long, Twitter cuts-off part of the name.