<table width="100%" style="max-width: 100%;">
<tr>
<td align="center">
<div style="width: 100%; display: inline-block;">
<!--[if (gte mso 9)|(IE)]>
<table width="600" align="center" cellpadding="0" cellspacing="0" border="0"><tr><td>
<![endif]-->
<table width="100%" cellpadding="0" cellspacing="0" style="max-width: 800px; background: green;">
<tr>
<td style="text-align: center; vertical-align: top; font-size: 0;">
<!--[if (gte mso 9)|(IE)]>
<table width="100%" align="center" cellpadding="0" cellspacing="0" border="0"><tr><td>
<![endif]-->
<div style="width: 300px; display: inline-block; vertical-align: top;">
<table width="100%" style="background: red;">
<tr>
<td style="font-size: 12px;">Hello!</td>
</tr>
</table>
</div>
<!--[if (gte mso 9)|(IE)]>
</td><td>
<![endif]-->
<div style="width: 300px; display: inline-block; vertical-align: top;">
<table width="100%" style="background: blue;">
<tr>
<td style="font-size: 12px;">Hello!</td>
</tr>
</table>
</div>
<!--[if (gte mso 9)|(IE)]>
</td></tr></table>
<![endif]-->
</td>
</tr>
</table>
<!--[if (gte mso 9)|(IE)]>
</td></tr></table>
<![endif]-->
</div>
</td>
</tr>
</table>