Lien mailto avec message

Trois intpbox avec celle du corps du messsage le defalut voulu...

<script>
function mailmoi() {
var tmp=document.forms["message"];
var action="mailto:"+tmp.elements['from'].value+"?subject="+tmp.elements['subject'].value +"&body="+tmp.elements['body'].value+"&attachment='"+tmp.elements['attach'].value+"'";
alert(action);
tmp.action=action;
tmp.submit();
}

//tmp=document.forms["message"];
//tmp.action="?php echo $action;?";
//tmp.submit();
</script>

<form name="message" ACTION="javascript:mailmoi();" METHOD="post" ENCTYPE="multipart/form-data">
<p>
<INPUT type="text" name="from" value="toi@mail.moi" size="20" />
</p>
<p>
<INPUT type="text" name="subject" value="sujet du mail" size="20" />
</p>
<p>
<textarea name="body" cols="100" rows="2"" onclick="envoi.disabled=false" >Message réconfortant</textarea>
</p>
<p> <INPUT TYPE="file" NAME="attach" > </p>
<p>
<input type="submit" name="envoi" value="ENVOI" />
</p>
</form>

<form action="mailto:user@example.com" method="get">
<input name="subject" type="hidden" value="Message Title">
<input name="cc" type="hidden" value="user2@example.com">
Feedback:<br/>
<textarea name=body cols="40">
Please share your thoughts here
and then choose Send Feedback.
</textarea>

<input type="submit" value="Send Feedback">
</form>

https://docs.microsoft.com/en-us/previous-versions//aa767737(v=vs.85)?redirectedfrom=MSDN

Bref creons un fichier eml ...