Version: 1
Type: Function
Category: Other
License: GNU General Public License
Description: Email regex validation with MX check and communication. Sample code included. Returns bool valid code, bool condition code and str message.
<?php //sample code //$eMail = "[email protected]"; //$IsItValid = validateEmail($eMail); //echo "<p>"; //$valid = (!$IsItValid[0]) ? "FALSE" : "TRUE"; //echo $eMail." is a valid email address: ".$valid."<br>n"; //$spcmsg = (!$IsItValid[1]) ? "FALSE" : "TRUE"; //echo "Special validation condition exists: ".$spcmsg."<br>n"; //$strmsg = $IsItValid[2]; //echo "Returned validation message: ".$strmsg."<br>n"; //echo "</p>n"; //exit; /* Function: validateEmail() Date: 02/03/2003 Usage: validateEmail(email_address,<$DEBUG=true>) Returns: array $Return $Return[0]: int 0 = invalid email int 1 = valid email $Return[1]: int 0 = no special validation condition int 1 = special validation condition exists $Return[2]: str 'text of return message' Platforms: Unix,Linux Versions: PHP3, PHP4 Notes: - Special Validation Conditions return TRUE based on criteria which make it impossible to validate an email address against a mail server. For example, these conditions may exist if MX records are munged or returned in an unexpected format, or if there is a system error preventing the lookup and extraction of the MX server, or if the answering mail server just refuses permission to logon (AOL mostly). */ function validateEmail($eMail,$DEBUG=false) { if (!$DEBUG) error_reporting(0); global $HTTP_HOST; $myhost = $HTTP_HOST; if ($DEBUG) echo "Checking format of ".$eMail.".<br>n"; //verify email address format if (!eregi("^[_a-z0-9_-]+(.[_a-z0-9_-]+)*@[a-z0-9_-]+(.[a-z0-9_-]+)*(.[a-z]{2,3})$", $eMail)) { //return with an invalid address error $returnMsg = $eMail." is an invalid email address format.<br><br>n"; if ($DEBUG) echo $returnMsg; $Return[0] = FALSE; $Return[1] = FALSE; $Return[2] = $returnMsg; return $Return; } else { if ($DEBUG) echo "Format of ".$eMail." verified.<br><br>n"; } list($userName,$domainName ) = split ("@",$eMail); $domainName = $domainName."."; if (checkdnsrr($domainName,"MX")) { if (getmxrr($domainName,$mxRecord)) { //save the MX hostname $mailSvr = $mxRecord[0]; } else { //MX record exists but failed to retrieve //return with a system error message NOT an invalid address //set special condition flag $Return[1] $returnMsg = "System error - problem with MX record lookup. Email address may be valid."; if ($DEBUG) echo $returnMsg; $Return[0] = TRUE; $Return[1] = TRUE; $Return[2] = $returnMsg; return $Return; } } else { //no MX record found, assume $domainName is also the mail server $mailSvr = $domainName; } if ($DEBUG) echo "Using mail server ".$mailSvr."...<br> <br>n"; if ($DEBUG) echo "Trying ".$mailSvr." on SMTP port 25...<br><br>n"; $Connection = fsockopen($mailSvr, 25, $errno, $errstr, 10); if ($Connection) { $InitConnect = fgets($Connection, 1024); if ($DEBUG) echo "Connection Made to ".$mailSvr.".<br><br>n"; if ($DEBUG) echo $mailSvr."> ".$InitConnect."<br><br>n"; //start the SMTP validation if (ereg("^220",$InitConnect)) { //it's a friendly SMTP server, start communication //store the response $mailOpenQ = "HELO " .$myhost. "rn"; fputs($Connection, "$mailOpenQ"); $mailOpenA = fgets($Connection, 1024); if ($DEBUG) echo $myhost."> ".$mailOpenQ."<br>n"; if ($DEBUG) echo $mailSvr."> ".$mailOpenA."<br><br>n"; //Ask it to accept mail from phpemailtester@$myhost //store the response $mailFromQ = "MAIL FROM: <phpemailtester@$myhost>rn"; fputs($Connection, "$mailFromQ"); $mailFromA = fgets($Connection,1024); if ($DEBUG) echo $myhost."> ".htmlspecialchars($mailFromQ)."<br>n"; if ($DEBUG) echo $mailSvr."> ".$mailFromA."<br><br>n"; //Ask it to accept mail for delivery to $eMail user //store the response $mailToQ = "RCPT TO: <$eMail>rn"; fputs($Connection, "$mailToQ"); $mailToA = fgets($Connection,1024); if ($DEBUG) echo $myhost."> ".htmlspecialchars($mailToQ)."<br>n"; if ($DEBUG) echo $mailSvr."> ".$mailToA."<br><br>n"; //Close the connection $mailQuit = "QUITrn"; fputs ($Connection, $mailQuit); socket_set_timeout($Connection,1,1); fclose($Connection); if ($DEBUG) echo $myhost."> ".$mailQuit."<br><br>n"; //look for a "250" response in $mailTo if (ereg("^250", $mailToA)) { // return with a successful validation $returnMsg = $mailSvr." replied that ".$eMail." exists or is, at least, syntactically correct.<br>n"; if ($DEBUG) echo $returnMsg; $Return[0] = TRUE; $Return[1] = FALSE; $Return[2] = $returnMsg; return $Return; } else { // the server refused the user so return with invalid address error $returnMsg = $mailSvr." returned bad or non-existent address error."; if ($DEBUG) echo $returnMsg; $Return[0] = FALSE; $Return[1] = FALSE; $Return[2] = $returnMsg; return $Return; } } else if (ereg("^550)", $InitConnect)) { //connected to an unfriendly mail server or received an error response //most likley from AOL, must accept $eMail as valid //set special condition flag $Return[1] if (ereg("aol.com$", $eMail) || ereg("AOL", $InitConnect)) { $returnMsg = "Unfriendly AOL mailserver (".$mailSvr.") - cannot verify ".$eMail.".<br>n"; } else { $returnMsg = "Unfriendly mail server (".$mailSvr.") will not let us verify ".$eMail.".<br>n"; } //attempt to close nicely anyway, if needed fputs ($Connection, "QUITrn"); fclose($Connection); if ($DEBUG) echo $returnMsg; $Return[0] = TRUE; $Return[1] = TRUE; $Return[2] = $returnMsg; return $Return; } else { //connection made, but it failed to identfy itself as an SMTP server //so return with an invalid address error $returnMsg = "Connected to ".$mailSvr.", but does not appear to be a mail server. Address verification fails."; //attempt to close nicely, if needed fputs ($Connection, "QUITrn"); fclose($Connection); if ($DEBUG) echo $returnMsg; $Return[0] = FALSE; $Return[1] = FALSE; $Return[2] = $returnMsg; return $Return; } } else { // the connection failed - return with an invalid address error $returnMsg = "Connection to ".$mailSvr." failed. Address verification fails."; if ($DEBUG) echo $returnMsg; $Return[0] = FALSE; $Return[1] = FALSE; $Return[2] = $returnMsg; return $Return; } } ?>
