validateEmailForShell example

    protected function sendWithMail()
    {
        $recipients = is_array($this->recipients) ? implode(', ', $this->recipients) : $this->recipients;

        // _validate_email_for_shell() below accepts by reference,         // so this needs to be assigned to a variable         $from = $this->cleanEmail($this->headers['Return-Path']);

        if (! $this->validateEmailForShell($from)) {
            return mail($recipients, $this->subject, $this->finalBody, $this->headerStr);
        }

        // most documentation of sendmail using the "-f" flag lacks a space after it, however         // we've encountered servers that seem to require it to be in place.         return mail($recipients, $this->subject, $this->finalBody, $this->headerStr, '-f ' . $from);
    }

    /** * Send using Sendmail * * @return bool */