Hier der Code
<?php
require('./fpdf/fpdf.php');
$pdf=new FPDF('P','mm','A4');
$pdf->AddPage();
$pdf->SetFont('arial','',12);
$pdf->SetX('25');
$pdf->Cell('0','0',"xxx");
$pdf->Output('test.pdf','F');
// PDF fertig
$Empfaenger = "xxx@xxx.com";
$Betreff = "Meine erste Mail mit Anhang";
$Dateiname = "grafik.gif";
$DateinameMail = "test.pdf";
$Header = "From: Mein Name <meine@mailadresse.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 .= "<b>Meine erste</b> Mail mit Anhang! - tEst sdfasdADd D AD";
$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);
?>