a possible part solution I've found that if I edit the MailSend.php from tools/swift/swift plugin and blank out the header & parameter bits from around line 160 to be: if (!ini_get("safe_mode")) $success = mail($to, $subject, $message, "", ""); else $success = mail($to, $subject, $message, ""); I can successfully get phpmail to work at shop setup (so assume it'll work at other times as well). Possibly this means the header info / params passed are creating the problem, or at least with my host (hostmonster). I don't know enough about php to see why but it seems similar to some posts saying to use params="".