If I choose to enable push proxy am I sending the Zooiper push proxy my VoIP account login and password or is a hash of the password being used in some way such that my account and password never leave my phone?
Hello,
Our PUSH service does not know your SIP account credentials, it just forwards the packets to the service provider. We do not have access to plaintext credentials.
You can find details regarding how the PUSH service works, here: https://www.zoiper.com/en/support/home/article/205/Zoiper_Push_Proxy