I'm having trouble getting images to be full width on: Android 4.4, Android 5.1, and Google IMAP (Android 4.4).

Gmail
<table class="w580" width="580" cellpadding="0" cellspacing="0" border="0" bgcolor="#ffffff">
    <tr>
        <td class="w580" width="580">
            <table cellpadding="0" cellspacing="0" border="0" align="left" class="w203txt" width="203">
                <tr>
                    <td>
                        <img editable src="http://placehold.it/280x280" label="Image" border="0" class="w193txt" width="193" />
                    </td>
                </tr>
            </table>
            <table cellpadding="0" cellspacing="0" border="0" align="left" class="w362txt" width="362">
                <tr>
                    <td class="w362txt" width="362">
                        <div align="left" class="sub-header">Header</div>
                        <div align="left" class="article-content">Text Content</div>
                    </td>
                </tr>
            </table>
        </td>
    </tr>
</table>

-- CSS --
@media only screen and (max-width: 580px) {
.w203txt { min-width: 100% !important; }
.w193txt { min-width: 100% !important; }
.w362txt { min-width: 100% !important; }
}

For all other mobile clients, the image spans the entire width (with padding on the left and right sides). I've tried just about everything under the sun to get these 3 clients to behave, and I'm not sure what else to do. If you have any idea,