In PHP, to have a checkbox group pass multiple values, the names of the checkboxes need to end with "[]" to create an array:
<label>
<input type="checkbox" name="Color[]" value="Red" id="Color_0" />
Red</label>
<br />
<label>
<input type="checkbox" name="Color[]" value="Green" id="Color_1" />
Green</label>
<br />
<label>
<input type="checkbox" name="Color[]" value="Blue" id="Color_2" />
Blue</label>
<br />
<label>
<input type="checkbox" name="Color[]" value="Yellow" id="Color_3" />
Yellow</label>
<br />
next, in the WA_UniversalEmail/Templates/contactus.php file, find the following line:
<?php echo(str_replace("\n","<BR />",$pval)); ?>
and change it to:
<?php if(is_array($pval)) { ?>
<?php echo(str_replace("\n","<BR />",implode(", ",$pval))); ?>
<?php } else { ?>
<?php echo(str_replace("\n","<BR />",$pval)); ?>
<?php } ?>