Hello everyone!
I've for a few days strange lines that appear under my images on Office 365 and Outlook.com. However, I've a display: block on my pictures, and, strange thing, everything is ok when I do a test in real! This bug appears only on Litmus or Email on Acid. When I add a style = "font-size: 0px" to the cell containing my image, the problem is fixed ... But why? Do you have an explanation? I would like to understand this fix, and not add it to my code without reason ...

Here is my code:

<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Document sans titre</title>
<table width="100%" border="0" cellspacing="0" cellpadding="0">
    <td align="center"><table width="600" border="0" cellspacing="0" cellpadding="0">
          <td bgcolor="#FFFF00"><img src="http://test.badsender.com/BADSENDER/R&D/images/visuel_01.jpg" width="600" height="400" border="0" style="display:block; font-family:Arial, Helvetica, sans-serif; font-size:20px; color:#000" alt="test01"></td>
          <td bgcolor="#00FFFF"><img src="http://test.badsender.com/BADSENDER/R&D/images/visuel_03.jpg" width="600" height="200" border="0" style="display:block;"></td>
          <td bgcolor="#FF00FF"><img src="http://test.badsender.com/BADSENDER/R&D/images/visuel_02.jpg" width="600" height="400" border="0" style="display:block;"></td>