Ok so I am in the process of moving PayPal recurring subscriptions from my vBulletin to aMember. PayPal does not allow you to change the IPN for existing recurring subscriptions, so those will still send the notification to vBulletin when I need it in aMember.
After lots of trial and error + browsing on here, I found a solution by another user that works:
# ensure only rewrite old paypal when query has exactly right parameter
RewriteCond %{QUERY_STRING} (?:^|&)method=paypal(?:$|&)
# should only happen on first request and allow the pretty url to be routed normally on the next pass through the rules
RewriteRule ^ aMember/payment/ipn [NS,DPI,QSD]
Now my question is this: Does this still allow the notification to hit the vBulletin software or is there anything I can do to allow that? Because if I could that would mean I would be able to have both running at the same time and allow me more flexibility in how I transfer people over...whereas in the current situation I would need to do them all at once.