Will the IPN notify URL passed to Paypal automatically be prefixed HTTPS when the Board URL is set to use it? If not, then the user will receive a warning about their details being insecurely transmitted. There is no mention of the URL used in the User Upgrade Transaction Log.
Not sure myself. But I wasn't aware of Paypal allowing non https traffic period. In fact the IPN is or has changed to require TLS 1.2 specifically in server to paypal transactions (not the clients browser).
The IPN URL is automatically prefixed with your Board URL. You can confirm this if you look at the source before going to make a payment (to see what's passed).
Thanks Mike, I just found it in the account_upgrades template too. Code: <input type="hidden" name="notify_url" value="{$xenOptions.boardUrl}/payment_callback.php" />
