Checkout Issue on Paypal: Invalid Email Address … Post author:larry Post published:Dec 20, 2005 Post category:Diary Check access rights for the key, certificate, and those directories holding these files! Not the email address issue, but the issue is that webserver can’t access the key or cert. thus it couldn’t pass it to Paypal. You Might Also Like GIMP No Transparent Background Mar 4, 2014 Background Feb 9, 2005 Deployment of WordPress Shopp Feb 18, 2014