Yet another way you can accomplish this and keep consistent spacing above and below the line is to add in a table with 2 rows and add a border to the bottom of the first cell, like below:
<p>This is text above the break</p>
<table cellpadding="0" cellspacing="0" width="100%">
<tr>
<td style="border-bottom:1px solid #ccc;"> </td>
</tr>
<tr>
<td> </td>
</tr>
</table>
<p>This is text below the break</p>
You can also control the space between the above text/image and the below text/image by adjusting the height of each row.