Short answer:
Email clients do not consistently support CSS. Use tables and spacer images to control layout and spacing reliably.
While web pages and emails both use HTML and CSS, email clients do not follow the same standards as modern browsers. Each email client uses its own rendering engine, which determines how your code is interpreted.
This means that many HTML tags and CSS properties behave differently—or are not supported at all—across email clients. For consistent results, traditional HTML techniques such as tables and spacer images are still recommended.
Example: Creating spacing using a fixed-height row (70pt)
<table border="1" cellpadding="0" cellspacing="0" style="border:none; mso-table-lspace:0pt; mso-table-rspace:0pt; border-collapse:collapse; width: 320px;">
<tbody>
<tr>
<td style="width: 320px;"><font color="#000000" face="Arial, Helvetica, Geneva, Sans-Serif" style="FONT-SIZE: 10pt">Best,</font></td>
</tr>
<tr>
<td><img border="0" height="70pt" src="/Images/Get/e1/d5.gif" width="1pt" /></td>
</tr>
<tr>
<td><font color="#000000" face="Arial, Helvetica, Geneva, Sans-Serif" style="FONT-SIZE: 10pt">((DisplayName))</font></td>
</tr>
</tbody>
</table>This method uses a transparent spacer image to enforce consistent vertical spacing across email clients.
Preview in Xink built-in editor:
