app/views/contact_mailer/contact_details.html.erb
<!DOCTYPE html>
<html>
<head>
<meta content='text/html; charset=UTF-8' http-equiv='Content-Type' />
</head>
<body>
<h1>Hi admin,</h1>
<p>
Workdey has a mail from <strong><%= @name.capitalize %></strong>. Please find the content below:
</p>
<p>
<h3>Sender's mail address:</h3>
</p>
<p>
<strong><%= @sender %></strong>.
</p>
<p>
<h3>Message:</h3>
</p>
<p>
<%= @message %>
</p>
<p>Cheers!</p>
</body>
</html>