Did you ever find a solution for this? I'm having the same issue on my site and I've found a bit of code around line 922 in the file plugins/phpmailer/class.phpmailer.php that seems like it was written to force wrap the messages and yet it isn't working (at least not for the broadcast message):
/**
* Wraps message for use with mailers that do not
* automatically perform wrapping and for quoted-printable.
* Original written by philippe.
* @param string $message The message to wrap
* @param integer $length The line length to wrap to
* @param boolean $qp_mode Whether to run in Quoted-Printable mode
* @access public
* @return string
*/
public function WrapText($message, $length, $qp_mode = false) {
$soft_break = ($qp_mode) ? sprintf(" =%s", $this->LE) : $this->LE;
// If utf-8 encoding is used, we will need to make sure we don't
// split multibyte characters when we wrap
$is_utf8 = (strtolower($this->CharSet) == "utf-8");
$message = $this->FixEOL($message);
So that didn't work. I even tried to insert a value in the same file at line 121:
/**
* Sets word wrapping on the body of the message to a given number of
* characters.
* @var int
*/
public $WordWrap = 0;
I changed this value to:
public $WordWrap = 50;
And that didn't work. So any suggestions would be great!