URL Decode or Base64 Encode/Decode

I am running into some trouble when I need to pass an input field with an email address as a URL query parameter as it is auto URL Encoded, when I try read the parameter back from the URL I either need to have a URL Decode to put the @ symbol back in my email address or alternatively I would need to base64 encode the parameter before sending it and base64 decode it back again.

Anyone run into an issue like this before and found a solution around it?