wordpress from email address invalid format

Hi,
I have installed wordpress for hte Ski club I am a member of and its all working great except for one issue. The new user emails and password reset emails are being sent out with the from address in an invalid format. I even installed the mail from plugin and that has not fixed it. The from adress line is being set as

from: <WordPress <wordpress@xxxx.co.uk>

which is being rejected. the mails that are sent from Fast Secure Contact Form were correct and get sent. I looked through pages of code (not a great PHP coded) and the only way i could fix it was to change the class-phpmailer.php CreateHeader function like this:-

//$result .= $this->AddrAppend('From', $from);
$result .= 'From: postmaster@Cotswoldski.co.uk>';

I have obviously done somethink stupid alond the way, could anyone suggest what i might have done to cause this?

Thanks

Ian…