I\'m trying to add image to mail body from folder.but it not display only display text on alt tag.this is my code.
You can either link to a fully qualified URL of the image, e.g. http://yourserver.com/images/image.png
Or, you can embed the image in your email using MIME. See this response: PHP Attaching an image to an email
You may choose whichever you want, still it is not guaranteed that the image will be displayed by the mail client - in most cases, the client decides whether it will or will not show the images.
This should work as expected:
<?php
...
$body .= '<img src="http://domain.com/absolute/path/to/image/img/logo.png" alt="Hotel" /><br/>';
...
?>