Why does Mail.ru cut the link in the email?

Question

Email

When registering on the site, the user receives an automatically generated email with a link to confirm the email.

$message = 'Для подтверждения EMAIL перейдите по ссылке: <strong><a href="'.SITE_SERVER_NAME.'/account/confirm.php?confirm='.md5($params['VALUE']).'">Подтвердить Email</a> </strong><br>';

For all mail systems, the link is correct and clickable, but if the mail was from mail.ru, then the link in the letter is cut off and it becomes like this:

<a target="_blank" rel=" noopener noreferrer">Подтвердить Email</a>

actually what's the matter? About three years ago, the same question was raised and the problem turned out to be in quotation marks, but here with them, it seems, everything is in order.

Answer 1

You don't have a protocol in href and it's generally a relative link (it doesn't start with //), so it's not valid for mail. By e-mail standards, the default scheme for emails, if not available, is file://. Form the correct full link with https://