//works
<p>Your loan specialist, {!User.FirstName} {!User.LastName}, will be contacting you promptly during business hours.</p>
//does not work
<a href="https://my.companywebsitename.com/?source=emailBZ&payload={!Lead.Encrypted_Email_String__c}" style="box-sizing: border-box; border-color: #EB8243; text-decoration: none;">Get Started</a>