Button
<table border="0" width="600" cellspacing="0" cellpadding="0" align="center">
<tbody>
<tr>
<td style="font-size: 15px; line-height: 15px;" height="15"></td>
</tr>
<tr>
<td>
<table style="background-color: #019b5f; border: 10px solid #019b5f; -webkit-border-radius: 5px; -moz-border-radius: 5px; border-radius: 5px;" border="0" width="175" cellspacing="0" cellpadding="0" align="center">
<tbody>
<tr>
<td align="center"><a style="color: #ffffff; display: inline-block; font-size: 20px; font-weight: bold; font-family: Arial, Helvetica, sans-serif; mso-line-height-rule: exactly; line-height: 20px; text-align: center; text-decoration: none; width: 175px; -webkit-text-size-adjust: none;" href="http://google.com">Accept Today</a></td>
</tr>
</tbody>
</table>
</td>
</tr>
<tr>
<td style="font-size: 10px; line-height: 10px;" width="600" height="10"></td>
</tr>
</tbody>
</table>
<tbody>
<tr>
<td style="font-size: 15px; line-height: 15px;" height="15"></td>
</tr>
<tr>
<td>
<table style="background-color: #019b5f; border: 10px solid #019b5f; -webkit-border-radius: 5px; -moz-border-radius: 5px; border-radius: 5px;" border="0" width="175" cellspacing="0" cellpadding="0" align="center">
<tbody>
<tr>
<td align="center"><a style="color: #ffffff; display: inline-block; font-size: 20px; font-weight: bold; font-family: Arial, Helvetica, sans-serif; mso-line-height-rule: exactly; line-height: 20px; text-align: center; text-decoration: none; width: 175px; -webkit-text-size-adjust: none;" href="http://google.com">Accept Today</a></td>
</tr>
</tbody>
</table>
</td>
</tr>
<tr>
<td style="font-size: 10px; line-height: 10px;" width="600" height="10"></td>
</tr>
</tbody>
</table>
Bulletproof button
<div><!-- [if mso]>
<v:roundrect xmlns:v="urn:schemas-microsoft-com:vml" xmlns:w="urn:schemas-microsoft-com:office:word" href="http://google.com" style="height:40px;v-text-anchor:middle;width:200px;" arcsize="5%" stroke="f" fillcolor="#4BC3F1">
<w:anchorlock/>
<center>
<![endif]-->
<a style="background-color: #4bc3f1; border-radius: 2px; color: #ffffff; display: inline-block; font-family: sans-serif; font-size: 13px; font-weight: bold; line-height: 40px; text-align: center; text-decoration: none; width: 200px; -webkit-text-size-adjust: none;" href="http://google.com">DOWNLOAD NOW</a>
<!-- [if mso]>
</center>
</v:roundrect>
<![endif]--></div>
<v:roundrect xmlns:v="urn:schemas-microsoft-com:vml" xmlns:w="urn:schemas-microsoft-com:office:word" href="http://google.com" style="height:40px;v-text-anchor:middle;width:200px;" arcsize="5%" stroke="f" fillcolor="#4BC3F1">
<w:anchorlock/>
<center>
<![endif]-->
<a style="background-color: #4bc3f1; border-radius: 2px; color: #ffffff; display: inline-block; font-family: sans-serif; font-size: 13px; font-weight: bold; line-height: 40px; text-align: center; text-decoration: none; width: 200px; -webkit-text-size-adjust: none;" href="http://google.com">DOWNLOAD NOW</a>
<!-- [if mso]>
</center>
</v:roundrect>
<![endif]--></div>
Bulletproof button without VML
<a href="http://test.com/" style="background-color: #7fc549; background-image: linear-gradient(to top, #56ab2f, #a8e063); border: 1px solid #4e9a2a; border-radius: 3px;
color: #ffffff; display: inline-block; font-family: sans-serif; font-weight: bold; mso-border-alt: 8px solid #7fc549; mso-padding-alt: 0; padding: 8px 16px; text-decoration: none;">All Buttoned Up</a>
color: #ffffff; display: inline-block; font-family: sans-serif; font-weight: bold; mso-border-alt: 8px solid #7fc549; mso-padding-alt: 0; padding: 8px 16px; text-decoration: none;">All Buttoned Up</a>