[RESOLVED] validating / testing e-mail address

[perpetualshaun]

I found a few things on various sites and combined them into one function that kinda works for me. I want a function that will check an e-mail address in the following ways:

1) Check that it's in the correct format
2) Check that the MX record exists
3) Test that the alias/username is valid

So here is the function I came up w/:

function checkEmail($email) {
	//echo "\$email: ".$email."<br />\n";

// checks proper syntax
if(eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)+$", $email)) {

	// gets domain name
	list($username,$domain)=split('@',$email);

	// checks for if MX records in the DNS
	if(!checkdnsrr($domain, 'MX')) {
		getmxrr($domain, $mxhosts);
		foreach($mxhosts as $mxKey => $mxValue) {
			echo '&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'.$mxValue.'<br>'."\n";
		}
		$error = "Failed the checkdnsrr!";
		return $error;
	}
	// attempts a socket connection to mail server
	$Connect = fsockopen ($domain, 25 );
	if ($Connect) {
		if (ereg("^220", $Out = fgets($Connect, 1024))) {
			fputs ($Connect, "HELO $HTTP_HOST\r\n");
			$Out = fgets ( $Connect, 1024 );
			fputs ($Connect, "MAIL FROM: <{$email}>\r\n");
			$From = fgets ( $Connect, 1024 );
			fputs ($Connect, "RCPT TO: <{$email}>\r\n");
			$To = fgets ($Connect, 1024);
			fputs ($Connect, "QUIT\r\n");
			fclose($Connect);
			if (!ereg ("^250", $From) || !ereg ( "^250", $To )) {
				$error = "Server rejected address";
				return $error;
			} 
		} else {
			$error = "No response from server";
			return $error;
		}
	} else {
		$error = "Cannot connect to the e-mail server.";
		return $error;
	}
}
return "no errors";
}

This function does exactly what I want to when I test some addresses. However, when I put in my Yahoo or GMail account, it returns an error; either the "No response from server" or "Cannot connect to the e-mail server". Does anyone know if there is something unique about executing the fsockopen() command to those mail servers? If so, maybe MSN, AOL and others need to connect on another socket?

Any ideas??

Thanks,
Shaun

[bpat1434]

Gmail uses a secure connection (SSL) (port 995) so port 25 will return an error... not sure about Yahoo! though.

Gmail uses a secure connection (SSL) for SMTP (465)... not sure about Yahoo! though.

Yahoo! Connection Info
Incoming Mail (POP3) Server: pop.mail.yahoo.co.uk (Port 110)

Outgoing (SMTP) Server: smtp.mail.yahoo.co.uk (Port 25)

REQUIRES USE OF SSL

And for an RFC properly formatted email validation pattern, check out the [man]eregi/man manual page and read the user notes. One is specifically from bobocop and the other is a couple posts after (as in temporally) or before (as in vertically) which gives you a really good validation rule. If you search for bobocop, you will find both posts.

[perpetualshaun]

I've done some more tweaking / testing on this function and it's getting closer. Here's what I have now:

function checkEmail($email) {
	$HTTP_HOST = $_SERVER['HTTP_HOST'];
	global $HTTP_HOST;
	$result = array();
	//echo "\$email: ".$email."<br />\n";

// checks proper syntax
if(eregi("^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)+$", $email)) {

	// gets domain name
	list($username,$domain)=split('@',$email);

	// checks for if MX records in the DNS
	if(!checkdnsrr($domain, 'MX')) {
		getmxrr($domain, $mxhosts);
		foreach($mxhosts as $mxKey => $mxValue) {
			echo '&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'.$mxValue.'<br>'."\n";
		}
		$result[0] = "FAIL";
		$result[1] = "Failed the checkdnsrr!";
	} else {
		if (getmxrr($domain, $MXHost))  {
			$ConnectAddress = $MXHost[0];
			foreach($MXHost as $mxKey => $mxValue) {
				echo '&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;'.$mxValue.'<br>'."\n";
			}
		} else {
			$ConnectAddress = $domain;
		}
	}

	// attempts a socket connection to mail server, first on port 25
	if(fsockopen ($ConnectAddress, 25 )) {
		$Connect = fsockopen ($ConnectAddress, 25 );
		if (ereg("^220", $Out = fgets($Connect, 1024))) {
			fputs ($Connect, "HELO ".$HTTP_HOST."\r\n");
			$Out = fgets ( $Connect, 1024 );
			fputs ($Connect, "MAIL FROM: <{$email}>\r\n");
			$From = fgets ( $Connect, 1024 );
			fputs ($Connect, "RCPT TO: <{$email}>\r\n");
			$To = fgets ($Connect, 1024);
			fputs ($Connect, "QUIT\r\n");
			fclose($Connect);
			if (!ereg ("^250", $From) || !ereg ( "^250", $To )) {
				$result[0] = "FAIL";
				$result[1] = "Server rejected address, on port 25";
			} 
		} else {
			$result[0] = "FAIL";
			$result[1] = "No response from server, on port 25";
		}
	} else {
		$result[0] = "FAIL";
		$result[1] = "Cannot connect to the e-mail server.";
	}
} else {
	$result[0] = "FAIL";
	$result[1] = "This is not a valid e-mail address.";
}
return $result;
}

Just a couple problems...

1) It returns an error every time from AOL, even though I know that some of the addresses I'm testing w/ are valid. Does anyone know if there is something unique about testing the fsocket on AOL?

2) It returns a failure from Yahoo... sometimes. It's really strange. I can use my own address and continue to hit the submit button on this form I have out there w/ this function and it'll return an error about half of the time. Why wouldn't it work every time?

Thanks,
Shaun

[bpat1434]

couldn't tell you. SOmething you'd have to look at server logs and such to figure out.