Gmail HTML length limit
<h1>Question</h1>

<p>Do you know if their is an html limit size with Gmail to keep the mail preview (in pixel or in number of characters) ?</p>

<hr>

<h1>Origin of the question</h1>

<p>In the picture below: </p>

<ul>
<li>The email received at 15:38 is display as ...</li>
<li>The email received at 15:46 is displayed in the preview.</li>
</ul>

<p>The only difference is the size of the mail content.</p>

<p><a href="https://i.stack.imgur.com/pMrdw.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/pMrdw.png" alt="enter image description here"></a></p>

<hr>

<p>Eventually, if it could help, the html of the 15:38 mail</p>

<p><div class="snippet" data-lang="js" data-hide="false" data-console="false" data-babel="false">
<div class="snippet-code">
<pre class="snippet-code-html lang-html prettyprint-override"><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&gt;
   &lt;head&gt;
      &lt;meta http-equiv="Content-Type" content="text/html; charset=utf-8"&gt;
   &lt;/head&gt;
   &lt;body style="margin: 0; padding: 0; font-size: 100%; font-family: 'Avenir Next', 'Helvetica Neue', 'Helvetica', Helvetica, Arial, sans-serif; line-height: 1.65; width: 100%; height: 100%; background: #efefef; -webkit-font-smoothing: antialiased; -webkit-text-size-adjust: none;"&gt;
      &lt;table class="body-wrap" style="margin: 0; padding: 0; font-size: 100%; font-family: 'Avenir Next', 'Helvetica Neue', 'Helvetica', Helvetica, Arial, sans-serif; line-height: 1.65; width: 100%; height: 100%; background: #efefef; -webkit-font-smoothing: antialiased; -webkit-text-size-adjust: none;"&gt;
         &lt;tr&gt;
            &lt;td class="container" style="display: block; clear: both; margin: 0 auto; max-width: 580px;"&gt;
               &lt;table style="border-collapse: collapse; width: 100%;"&gt;
                  &lt;tr&gt;
                     &lt;td align="center" class="masthead" style="padding: 10px 0; background: #C50929; color: white;"&gt;
                        &lt;h1 style="margin-bottom: 20px; line-height: 1.25; font-size: 32px; max-width: 90%; text-transform: uppercase; margin: 0 auto;"&gt;IDÉAL CARGO&lt;br&gt;Trailer demand&lt;/h1&gt;
                     &lt;/td&gt;
                  &lt;/tr&gt;
                  &lt;tr&gt;
                     &lt;td class="content" style="background: white; padding: 10px 35px;"&gt;
                        &lt;h3 style="margin-bottom: 20px; line-height: 1.25; font-size: 24px;"&gt;Customer request&lt;/h3&gt;
                        &lt;table class="display_info" style="border-collapse: collapse; width: 100%;"&gt;
                           &lt;tr style="color: #666B85; border-top: none;"&gt;
                              &lt;td align="left" style="padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1); background: #EBEBEB;"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; Trailer &lt;/p&gt;
                              &lt;/td&gt;
                              &lt;td align="left" style="padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1); border-right: 0px; background: #EBEBEB;"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; Classic &lt;/p&gt;
                              &lt;/td&gt;
                           &lt;/tr&gt;
                           &lt;tr style="border-top: 1px solid #C1C3D1; color: #666B85;"&gt;
                              &lt;td align="left" style="background: #FFFFFF; padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1);"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; Zone &lt;/p&gt;
                              &lt;/td&gt;
                              &lt;td align="left" style="background: #FFFFFF; padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1); border-right: 0px;"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; Sport Zone &lt;/p&gt;
                              &lt;/td&gt;
                           &lt;/tr&gt;
                           &lt;tr style="border-top: 1px solid #C1C3D1; color: #666B85;"&gt;
                              &lt;td align="left" style="padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1); background: #EBEBEB;"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; Dealer &lt;/p&gt;
                              &lt;/td&gt;
                              &lt;td align="left" style="padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1); border-right: 0px; background: #EBEBEB;"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; ATTACHES CHATEAUGUAY &lt;/p&gt;
                              &lt;/td&gt;
                           &lt;/tr&gt;
                           &lt;tr style="border-top: 1px solid #C1C3D1; color: #666B85;"&gt;
                              &lt;td align="left" style="background: #FFFFFF; padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1);"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; Question &lt;/p&gt;
                              &lt;/td&gt;
                              &lt;td align="left" style="background: #FFFFFF; padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1); border-right: 0px;"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; Blablabla aljfn uh iq fiqbef jhbh hh qjhe bwrh piv paiueh fak zcyb hzph paub ya pbh au dhalsk pvy^tefs &lt;/p&gt;
                              &lt;/td&gt;
                           &lt;/tr&gt;
                           &lt;tr style="border-top: 1px solid #C1C3D1; color: #666B85;"&gt;
                              &lt;td align="left" style="padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1); background: #EBEBEB;"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; Name &lt;/p&gt;
                              &lt;/td&gt;
                              &lt;td align="left" style="padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1); border-right: 0px; background: #EBEBEB;"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; Grand schtroumpf &lt;/p&gt;
                              &lt;/td&gt;
                           &lt;/tr&gt;
                           &lt;tr style="border-top: 1px solid #C1C3D1; color: #666B85;"&gt;
                              &lt;td align="left" style="background: #FFFFFF; padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1);"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; Email &lt;/p&gt;
                              &lt;/td&gt;
                              &lt;td align="left" style="background: #FFFFFF; padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1); border-right: 0px;"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; abec@gmail.com &lt;/p&gt;
                              &lt;/td&gt;
                           &lt;/tr&gt;
                           &lt;tr style="border-top: 1px solid #C1C3D1; color: #666B85;"&gt;
                              &lt;td align="left" style="padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1); background: #EBEBEB;"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; Phone &lt;/p&gt;
                              &lt;/td&gt;
                              &lt;td align="left" style="padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1); border-right: 0px; background: #EBEBEB;"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; 123 456 789 &lt;/p&gt;
                              &lt;/td&gt;
                           &lt;/tr&gt;
                           &lt;tr style="border-top: 1px solid #C1C3D1; color: #666B85; border-bottom: none;"&gt;
                              &lt;td align="left" style="background: #FFFFFF; padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1); border-bottom-left-radius: 3px;"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; City &lt;/p&gt;
                              &lt;/td&gt;
                              &lt;td align="left" style="background: #FFFFFF; padding: 5px; text-align: left; vertical-align: middle; font-weight: 300; font-size: 18px; text-shadow: -1px -1px 1px rgba(0,0,0,0.1); border-right: 0px; border-bottom-right-radius: 3px;"&gt;
                                 &lt;p style="font-size: 16px; font-weight: normal;"&gt; Las vegas &lt;/p&gt;
                              &lt;/td&gt;
                           &lt;/tr&gt;
                        &lt;/table&gt;
                     &lt;/td&gt;
                  &lt;/tr&gt;
               &lt;/table&gt;
            &lt;/td&gt;
         &lt;/tr&gt;
         &lt;tr&gt;
            &lt;td class="container" style="display: block; clear: both; margin: 0 auto; max-width: 580px;"&gt;
               &lt;table style="border-collapse: collapse; width: 100%;"&gt;
                  &lt;tr&gt;
                     &lt;td class="content footer" align="center" style="padding: 10px 35px; background: none;"&gt;
                        &lt;p style="font-weight: normal; font-size: 14px; margin-bottom: 0; color: #888; text-align: center;"&gt; Send by&lt;a href="http://www.idealtrailer.com/" style="color: #888; text-decoration: none; font-weight: bold;"&gt; Idéal Cargo&lt;/a&gt;&lt;/p&gt;
                     &lt;/td&gt;
                  &lt;/tr&gt;
               &lt;/table&gt;
            &lt;/td&gt;
         &lt;/tr&gt;
      &lt;/table&gt;
   &lt;/body&gt;
&lt;/html&gt;</code></pre>
</div>
</div>
</p>