once registered an email is sent with a pdf doc

I have achieved this by simply adding my own hooks into the email notification code and modifying the GFCommon::send_email method to accept an array of attachments and pass these to the wp_mail function, which supports attachments anyway.

Within the method GFCommon::send_user_notification :

$attachments = apply_filters("gform_user_notification_attachments_{$form_id}", $lead, $form);

self::send_email($from, $to, $bcc, $reply_to, $subject, $message, $from_name, $message_format, $attachments);

and within the method GFCommon::send_admin_notification :

$attachments = apply_filters("gform_admin_notification_attachments_{$form_id}", $lead, $form);

self::send_email($from, $to, $bcc, $reply_to, $subject, $message, $from_name, $message_format, $attachments);

And finally within the GFCommon::send_email method:

$result = wp_mail($to, $subject, $message, $headers, $attachments);

In my scenario, I am generating two personalised PDF documents for them to sign and return by post (old school, I know). I am populating PDF forms by mapping my Gravity Forms to XFDF and using the command-line tool pdftk to bind the XFDF data with my PDF... saving the result(s) as tmp file(s) so that it can be attached to the email.

Since this approach completely de-couples email attachments from your product, is this something you would look at baking into the codebase... it would certainly ease my update woes and will probably be rather useful to others too!

Thanks for that. My stand point is that by offering a hook for developers to add an attachment, you are by no means liable for any problems which may crop up with the overhead that this may impose on the server.. and importantly you need not rush into officially supporting email attachments as part of your offering and are instead offering a helping hand to those that wish to incorporate email attachments themselves, and at their own risk. It would be great to see this in the next release - it so light-weight that I suspect it would carry little or no risk at all to the stability of Gravity Forms and by simply relying on the tried and tested Wordpress filters (which you use to manipulate the to email address anyway) - apologies if I appear pushy, I may have gotten a little over-excited about this :)