Found that the email spam test in ACYMail 5 (5.10.14) that the Tracking image had a missing inverted comma in the code base. Causing the Spamtest to dock you 0.5 points when it should be 10/10
The error is in the file: ./plugins/acymailing/stats/stats.php
Line 59:
$statPicture = '<img class="spict" alt="'.$this->params->get('alttext', '').'" src="'.$pictureLink.'" border="0" '.$height.$width.'/>';
Change it to:
$statPicture = '<img class="spict" alt="track"'.$this->params->get('alttext', '').'" src="'.$pictureLink.'" border="0" '.$height.$width.'/>';
Problem fixed. AcyMail - please fix in the next release. Ta