收集一个smtp发信的php函数，已经测试

echo send_mail('[email protected]','发信标题','发信内容'); 

function send_mail($to, $subject = 'No subject', $body) { 
$loc_host = "#"; //发信计算机名，可随意 
$smtp_acc = "#"; //Smtp认证的用户名， 
$smtp_pass="password"; //Smtp认证的密码，一般等同pop3密码 
$smtp_host="#"; //SMTP服务器地址，类似 smtp.tom.com 
$from="#"; //发信人Email地址，你的发信信箱地址 
$headers = "Content-Type: text/plain; charset=\"gb2312\"\r\nContent-Transfer-Encoding: base64"; 
$lb="\r\n"; //linebreak 

$hdr = explode($lb,$headers); //解析后的hdr 
if($body) {$bdy = preg_replace("/^\./","..",explode($lb,$body));}//解析后的Body 

$smtp = array( 
//1、EHLO，期待返回220或者250 
array("EHLO ".$loc_host.$lb,"220,250","HELO error: "), 
//2、发送Auth Login，期待返回334 
array("AUTH LOGIN".$lb,"334","AUTH error:"), 
//3、发送经过Base64编码的用户名，期待返回334 
array(base64_encode($smtp_acc).$lb,"334","AUTHENTIFICATION error : "), 
//4、发送经过Base64编码的密码，期待返回235 
array(base64_encode($smtp_pass).$lb,"235","AUTHENTIFICATION error : ")); 
//5、发送Mail From，期待返回250 
$smtp[] = array("MAIL FROM: <".$from.">".$lb,"250","MAIL FROM error: "); 
//6、发送Rcpt To。期待返回250 
$smtp[] = array("RCPT TO: <".$to.">".$lb,"250","RCPT TO error: "); 
//7、发送DATA，期待返回354 
$smtp[] = array("DATA".$lb,"354","DATA error: "); 
//8.0、发送From 
$smtp[] = array("From: ".$from.$lb,"",""); 
//8.2、发送To 
$smtp[] = array("To: ".$to.$lb,"",""); 
//8.1、发送标题 
$smtp[] = array("Subject: ".$subject.$lb,"",""); 
//8.3、发送其他Header内容 
foreach($hdr as $h) {$smtp[] = array($h.$lb,"","");} 
//8.4、发送一个空行，结束Header发送 
$smtp[] = array($lb,"",""); 
//8.5、发送信件主体 
if($bdy) {foreach($bdy as $b) {$smtp[] = array(base64_encode($b.$lb).$lb,"","");}} 
//9、发送“.”表示信件结束，期待返回250 
$smtp[] = array(".".$lb,"250","DATA(end)error: "); 
//10、发送Quit，退出，期待返回221 
$smtp[] = array("QUIT".$lb,"221","QUIT error: "); 

//打开smtp服务器端口 
$fp = @fsockopen($smtp_host, 25); 
if (!$fp) echo "<b>Error:</b> Cannot conect to ".$smtp_host."<br>"; 
while($result = @fgets($fp, 1024)){if(substr($result,3,1) == " ") { break; }} 

$result_str=""; 
//发送smtp数组中的命令/数据 
foreach($smtp as $req){ 
//发送信息 
@fputs($fp, $req[0]); 
//如果需要接收服务器返回信息，则 
if($req[1]){ 
//接收信息 
while($result = @fgets($fp, 1024)){ 
if(substr($result,3,1) == " ") { break; } 
}; 
if (!strstr($req[1],substr($result,0,3))){ 
$result_str.=$req[2].$result."<br>"; 
} 
} 
} 
//关闭连接 
@fclose($fp); 
return $result_str; 
} 
?>