Emails not centering on iphone 5 and 6
<p>I'm trying to get my emails to be centered when they're opened on mobile devices. It seems like it's working on all devices right now except on the iPhone. I've tested it on the 5 (it skews left) and the 6/6s (it skews right). The issue looks like it's only happening on the native mail app. 
We'll be moving to responsive emails in the future, but for now we're using these HTML image/table based emails (unfortunately). </p>

<pre><code>&lt;!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"&gt;
&lt;html xmlns="http://www.w3.org/1999/xhtml"&gt;

&lt;head&gt;
    &lt;meta http-equiv="Content-Type" content="text/html; charset=utf-8" /&gt;
    &lt;meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1" /&gt;

&lt;title&gt;Email Title&lt;/title&gt;
&lt;meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"&gt;
&lt;meta name="title" content="Email Title"&gt;
&lt;meta name="description" content="Email Title"&gt;

&lt;style media="all" type="text/css"&gt;
    table img {
        display: block;
    }

    body {
        width: 100% !important;
        -webkit-text-size-adjust: 100%;
        -ms-text-size-adjust: 100%;
        margin: 0;
        padding: 10px 20px;
    }

    .ReadMsgBody {
        width: 100%;
    }

    .ExternalClass p,
    .ExternalClass span,
    .ExternalClass font,
    .ExternalClass td {
        line-height: 100%
    }

    table {
        border-collapse: collapse;
        mso-table-lspace: 0pt;
        mso-table-rspace: 0pt;
        padding: 0;
    }

    table td {
        border-collapse: collapse;
    }

    p {
        margin: 0 auto;
        text-align: center;
    }
&lt;/style&gt;
&lt;/head&gt;
&lt;body style="background-color: #ffffff; font-size: 10px; color: gray; font-family: Verdana, Arial, San-Serif, Geneva;"&gt;
    &lt;table width="100%" border="0" cellspacing="0" cellpadding="0"&gt;
        &lt;tr&gt;
            &lt;td align="center"&gt;

            &lt;table width="640" align="center"&gt;
                &lt;tr&gt;
                    &lt;td&gt;
                        &lt;table width="640" border="0" cellspacing="0" cellpadding="0" align="center"&gt;
                            &lt;tr&gt;
                                &lt;td align="left" style="padding:0;"&gt;
                                    &lt;font face="Helvetica, sans-serif" style="font-size:12px; color:#b4b4b4;font-weight:400;"&gt;&lt;a style="color:#b4b4b4;" href=""&gt;Shop&lt;/a&gt;&lt;/font&gt;
                                &lt;/td&gt;
                                &lt;td align="right" style="padding:0;"&gt;
                                    &lt;font face="Helvetica, sans-serif" style="font-size:12px; color:#b4b4b4;font-weight:400;"&gt;&lt;a style="color:#b4b4b4;" href=""&gt;Women's&lt;/a&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;/font&gt;
                                    &lt;font face="Helvetica, sans-serif" style="font-size:12px; color:#b4b4b4;font-weight:400;"&gt;&lt;a style="color:#b4b4b4;" href=""&gt;Men's&lt;/a&gt;&amp;nbsp;&amp;nbsp;&amp;nbsp;&lt;/font&gt;
                                    &lt;font face="Helvetica, sans-serif" style="font-size:12px; color:#b4b4b4;font-weight:400;"&gt;&lt;a style="color:#b4b4b4;" href=""&gt;Apartment&lt;/a&gt;&lt;/font&gt;
                                &lt;/td&gt;
                            &lt;/tr&gt;
                        &lt;/table&gt;
                    &lt;/td&gt;
                &lt;/tr&gt;
            &lt;/table&gt;
            &lt;br&gt;


            &lt;!--Dynamic header--&gt;
            &lt;!-- logo --&gt;
            &lt;table align="center" border="0" cellpadding="0" cellspacing="0" width="640"&gt;
                &lt;tr&gt;
                    &lt;td width="640"&gt;
                        &lt;a href=""&gt;&lt;img src="" border="0" alt="" width="640" height="45" style="display:block"&gt;
                        &lt;/a&gt;
                    &lt;/td&gt;
                &lt;/tr&gt;
            &lt;/table&gt;

            &lt;!--Begin Email--&gt;

            &lt;table align="center" border="0" cellpadding="0" cellspacing="0" width="640"&gt;
                &lt;tr&gt;
                    &lt;td&gt;
                        &lt;a href=""&gt;
                            &lt;img src="" style="display:block;" border="0" alt="graphic1"&gt;
                        &lt;/a&gt;
                    &lt;/td&gt;
                &lt;/tr&gt;
            &lt;/table&gt;                



            &lt;table align="center" border="0" cellpadding="0" cellspacing="0" width="100%" class="spacing"&gt;
                &lt;tr&gt;
                    &lt;td height="10px"&gt;&amp;nbsp;&lt;/td&gt;
                &lt;/tr&gt;
            &lt;/table&gt;
    &lt;/body&gt;
&lt;/html&gt;   
</code></pre>

<p>I feel like I've tried just about everything, including using a <code>&lt;center&gt;</code> tag, but nothing makes it budge.</p>

<p>ETA: Here is a screenshot of what it looks like on iOS 9
<a href="http://i.stack.imgur.com/944SZ.png" rel="nofollow">Example</a></p>