I'm facing a strange issue. My vps from Linode has no issue connecting to apple push server with following command. openssl s_client -connect gateway.sandbox.push.apple.com:2195 -cert Test_dev_apns_cert.pem -key Test_dev_apns_key.pem However, I was using the same pem files with above command testing from my another low budget vps and I'm getting this: Verify return code: 20 (unable to get local issuer certificate) Both are running Ubuntu 11.04 and installed LAMP as usual. No special configuration is done to both servers for SSL. Am I missing something here?