Why there are no any link to my site in content of my email?

In my laravel 5.7 app I use snowfire/beautymail templates and themsaid/laravel-mail-preview plugin for testing of emails sending at my local laptop.

In content of my email I point to my site with url like

<p class="email_title">
  You sent contact us message at <a href="" target="_blank" class="a_link"></a>{!! $site_name !!} site successfully !
</p>

I made check that these 2 variables are not empty, but checking email at my local disk when working at my local laptop with laravel-mail-preview enabled and sending emails using configured smtp there are no any link to my site in content of my email.

I have smtp installed. In .env of my server app:

MAIL_DRIVER=smtp 
MAIL_HOST=smtp.gmail.com 
MAIL_PORT=587 
MAIL_ENCRYPTION=tls

I check recieved emails on yahoo.com, gmail.com accounts.

Why links are not visible ?

Thanks!

via Chebli Mohamed