I am currently working on an open source dating script. But I have one bug that I just can't seem to fix.

I am unable to send system generated emails to Yahoo! and gmail.

I have done a lot of searching online, but can't seem to get it working. I have noticed that this could be something to do with the headers, in the sendMimemail.php the headers are:

                // Get flat representation of headers, parsing
                // Cc and Bcc as we go
                foreach ($this->headers as $name => $value) {
                    if ($name == 'Cc' OR $name == 'Bcc') {
                        $addresses = Mail_RFC822::parseAddressList($value, $this->smtp_params['helo'], null, false);
                        foreach ($addresses as $address) {
                            $smtp_recipients[] = sprintf('%s@%s', $address->mailbox, $address->host);
                        }
                    }
                    if ($name == 'Bcc') {
                        continue;
                    }
                    $headers[] = $name . ': ' . $this->encodeHeader($value, $this->build_params['head_charset']);
                }
                // Add To header based on $recipients argument
                $headers[] = 'To: ' . $this->encodeHeader(implode(', ', $recipients), $this->build_params['head_charset']);

                // Add headers to send_params
                $send_params['headers']    = $headers;
                $send_params['recipients'] = array_values(array_unique($smtp_recipients));
                $send_params['body']       = $this->output;

                // Setup return path
                if (isset($this->return_path)) {
                    $send_params['From'] = $this->return_path;
                } elseif (!empty($this->headers['From'])) {
                    $From = Mail_RFC822::parseAddressList($this->headers['From']);
                    $send_params['From'] = sprintf('%s@%s', $From[0]->mailbox, $From[0]->host);
                } else {
                    $send_params['From'] = 'postmaster@' . $this->smtp_params['helo'];
                }

But it just isn't getting to Yahoo! and gmail. Any ideas what the issue is? Any help would be appreciated.

You could add this code somewhere at the end of the snippet above:

die('<pre>' . print_r($send_params, 1) . '</pre>');

This will display array of the final version of all parameters needed for sending. Now you can go through each element and check it. Carefuly look at the $send_params['headers'] if it is assembled correctly. You can also post the output here fo us to look at it.