$Empfaenger = "info@email.de";
$Betreff = "Meine erste Mail mit Anhang";
$Dateiname = "$file";
$DateinameMail = "anhang.gif";

$Header = "From: Mein Name <info@email.de>";
$Trenner = md5(uniqid(time()));
$Header .= "\n";
$Header .= "MIME-Version: 1.0";
$Header .= "\n";
$Header .= "Content-Type: multipart/mixed; boundary=$Trenner";
$Header .= "\n\n";
$Header .= "This is a multi-part message in MIME format";
$Header .= "\n";
$Header .= "--$Trenner";
$Header .= "\n";
$Header .= "Content-Type: text/plain";
$Header .= "\n";
$Header .= "Content-Transfer-Encoding: 8bit";
$Header .= "\n\n";
$Header .= "Meine erste Mail mit Anhang!";
$Header .= "\n";
$Header .= "--$Trenner";
$Header .= "\n";
$Header .= "Content-Type: image/gif; name=$DateinameMail";
$Header .= "\n";
$Header .= "Content-Transfer-Encoding: base64";
$Header .= "\n";
$Header .= "Content-Disposition: attachment; filename=$DateinameMail";
$Header .= "\n\n";
$Dateiinhalt = fread(fopen($Dateiname, "r"), filesize($Dateiname));
$Header .= chunk_split(base64_encode($Dateiinhalt));
$Header .= "\n";
$Header .= "--$Trenner--";

mail($Empfaenger, $Betreff, "", $Header);