生成的电子邮件中的链接未显示为可点击

I am trying to send email - which is working correctly, but my "Click Here" link doesn't appear as click-able when it's received.

The code I am using is below

$to = $email;
$subject = "Activation";
$message = "We send you an activation email" .'<br>'.' To activate your acount. <a href="activation.php?key='.$key.'">Click Here</a>';
$from = "riaz_qadeer90@yahoo.com";
$headers .= 'Content-type: text/html; charset=iso-8859-1' . "
";
if(mail($to,$subject,$message,$headers))
{
    echo "Check your email to activate your acount.";
}

and mail is like this:

We send you an activation email To activate your acount. "Click Here"

but "Click Here" Link is not click-able

This could be down to your client disabling links in email addresses, but it's doubtful.

Also, the HREF of "Activation.PHP?Key.." is a relative path, that would only be relative to the email client, so the client would not know where to redirect the user to.

Adding a fully qualified path should help on this one.

Its likely to not be clickable as there is no slash before the page name.

However, the href should include your domain as the user will not be able to follow a relative path from an email.

In your href, coud you put the entire domain name end check again. example(href='http://mydomain.com/activation.php?key=.....