PHPMailer - Certain SMTP messages don't send - php

Question

I have a script that sends emails to users, which are sometimes divided into multiple messages depending on size. Here's the code:
for($i=0; $i<count($the_message); $i++){
$mail = new PHPMailer(true);
$mail->IsSMTP();
$mail->SMTPDebug = 1;
$mail->Host = "my.smtp.server";
$mail->Port = $email_port;
$mail->Username = "my#email.com";
$mail->Password = "mypassword";
$mail->SMTPAuth = true;
$mail->From = $from;
$mail->FromName = "My Name";
$mail->IsHTML($is_html);
if($is_html === TRUE){
$mail->AltBody = "To view the message, please use an HTML compatible email client, or change your export to a plain text format.";
}
foreach($to as $address){
$mail->AddAddress($address);
}
$mail->Body = $the_message[$i];
$mail->Subject = $the_sub;
$mail->Send();
}
This used to work great. Now, it seems that certain messages will never send. It seems to be a data issue (or perhaps the way PHPMailer sends lines to the server?), but I can't pinpoint why certain message segments are always rejected by the server.
The error message I get from PHPMailer is this:
SMTP Error: Data not accepted.
And from PHP itself:
Notice: fputs(): send of 31 bytes failed with errno=104 Connection
reset by peer in class.smtp.php on line 580
Here is a segment of HTML data that always fails to send:
http://pastebin.com/LGYkTTFA
Note that size isn't an issue, I can successfully send much larger HTML messages than this. However, when I send multiple segments, this one is never accepted by the server.

Answer 1

Here, I rewrote it for you in a somewhat saner way. You don't need to create everything from scratch every time around the loop, just change the body and send again.
<?php
require 'PHPMailerAutoload.php';
$the_message = array('Hello', 'there', 'Justin');
$to = array('tom#example.com', 'dick#example.net', 'harry#example.org');
$the_sub = 'Crazy subject';
$email_port = 25;
$from = 'justin#example.com';
$is_html = true;
$mail = new PHPMailer(true);
$mail->IsSMTP();
$mail->SMTPDebug = 1;
$mail->Host = "localhost";
$mail->Port = $email_port;
$mail->Username = "my#email.com";
$mail->Password = "mypassword";
$mail->SMTPAuth = true;
$mail->From = $from;
$mail->FromName = "My Name";
$mail->Subject = $the_sub;
$mail->IsHTML($is_html);
$mail->WordWrap = 200;
if($is_html){
$mail->AltBody = "To view the message, please use an HTML compatible email client, '.
'or change your export to a plain text format.";
}
foreach($to as $address){
$mail->AddAddress($address);
}
for($i=0; $i<count($the_message); $i++){
$mail->Body = $the_message[$i];
$mail->setWordWrap();
$mail->Send();
}
Update: added word wrapping to deal with content with very long lines.

Answer 2

In class.smtp.php, line 51, I changed the constant MAX_LINE_LENGTH from 998 to 500. This allowed all of my email segments to pass through.
I'm still not sure if the issue lies with my SMTP server or PHPMailer, I'll have to test it elsewhere.
EDIT: Tested using Gmail's SMTP server, and keeping 998 worked fine. This leads me to assume that my SMTP relay server is rejecting data sometimes depending on the length.
EDIT2: Still experienced failures with the above fix. I changed my port number and added SSL, and it is magically working. Wonky server issues...