powershell to send html and hyperlinks to users

my current script sends out plain text users:

$body = "test here`n`n"
$body += "and continues here."

i need include html , urls now. giving users redirects internal site , highlight text in red.

its 10 sentences long.

thank you

$body = get-content "d:\body.txt" | out-string

send-mailmessage -to $emailto -from $emailfrom -subject $subject -bodyashtml $body -smtpserver $smtpserver

Windows Server  >  Windows PowerShell