I'm trying to keep these images side by side, in both desktop and mobile, and it's not working in Outlook 2007, 2010, etc. There is a large gap between the two columns containing images, and the images expand outside the set width I created. It works in every other ESP, except older versions of Outlook (of course). Can you tell me what I'm doing wrong?
<!DOCTYPE html>
<html>
<head>
<title>Email</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<style>
body, table, td, a{-webkit-text-size-adjust: 100%; -ms-text-size-adjust: 100%;} /* Prevent WebKit and Windows mobile changing default text sizes */
table, td{mso-table-lspace: 0pt; mso-table-rspace: 0pt;} /* Remove spacing between tables in Outlook 2007 and up */
img{-ms-interpolation-mode: bicubic;} /* Allow smoother rendering of resized image in Internet Explorer */
img{border: 0; height: auto; line-height: 100%; outline: none; text-decoration: none;}
table{border-collapse: collapse !important; width: 100% !important; border-collapse: collapse; mso-table-lspace: 0; mso-table-rspace: 0; align-items: center;}
td {border-collapse: collapse !important;}
body{height: 100% !important; margin: 0 !important; padding: 0 !important; width: 100% !important;}
a[x-apple-data-detectors] {
color: inherit !important;
text-decoration: none !important;
font-size: inherit !important;
font-family: inherit !important;
font-weight: inherit !important;
line-height: inherit !important;
}
@media screen and (max-width: 525px) {
.header-img1 {
max-width: 425px !important;
width: 100% !important;
height: auto !important;
}
.header-img2 {
max-width: 175px !important;
width: 100% !important;
height: auto !important;
}
.header-td {
max-width: 425px !important;
width: auto !important;
height: auto !important;
padding: 0px !important;
margin: 0px !important;
}
}
<!--[if (gte mso 9)|(IE)]>
<table border="0" cellspacing="0" cellpadding="0" width="600">
<tr>
<td align="left" valign="bottom" width="600">
<![endif]-->
<table cellpadding="0" cellspacing="0" border="0" width="100%" style="max-width: 600px;">
<tr>
<td align="left" valign="bottom">
<table cellpadding="0" cellspacing="0" border="0" width="600" style="max-width: 600px; width: 600px;">
<tr>
<td align="left" valign="bottom" width="70%" style="max-width: 425px;" class="header-td">
<a href="#" target="_blank">
<img src="" style="display: block; width: 425px;" alt="" class="header-img1"></a>
</td>
<td align="left" valign="bottom" width="30%" style="max-width: 175px;" class="header-td">
<a href="#" target="_blank">
<img src="" alt="" style="display: block; width: 175px;" class="header-img2"></a>
</td>
</tr>
</table>
</td>
</tr>
</table>
<!--[if (gte mso 9)|(IE)]>
</td>
</tr>
</table>
<![endif]-->
The issue is coming from your css. You've set width to 100% and important, so it's overriding your fixed 600px widths. This alongside Outlook not supporting max-width is what's making your tables expand to full width.
table{border-collapse: collapse !important; width: 100% !important; border-collapse: collapse; mso-table-lspace: 0; mso-table-rspace: 0; align-items: center;}
Just remove the width: 100% !important and you'll be good to go. Also align-items: center should be removed, as it's part of flexbox and has zero support in emails. If you want your tables to be aligned center, then add align="center" as an attribute to the table (or on a td to center align within that).
Another minor thing, you might want to change the td widths to a fixed width that matches your image width.