I think you misunderstood something here.
hyperref is designed to add a clickable link into the internet to allow to open a special website or to open a mail program to send an email to the defined address.
A computer, exactly an operating system (Linux, Unix, OS x or Windows), can do this only if the information is provided which protocol is used for this service.
So an URL has to be something like that:
protocol://domain.top level domain or email@address
The protocols are
http (web side),
https (secure connection to website),
mailto (email) or
ftp (down- and uploads with ftp server) and others, named in the rfc files.
hello is there not named!
http://tex.stackexchange.com The url for this site
https://tex.stackexchange.com Secure connection to this site
mailto://email@example.com Send email to adress
The operating system can now start -- after knowing the protocol -- the corresponding program. For
http etc the used internet browser, for
mailto the installed email program. Both, browser and email program are different for different OSs and users. Nevertheless, protocol
mailto is known by each operating system, your wanted
That you have to click on that link is a thing of security, or do you want to get a pdf, filled with thousands of virus containing web pages or other bad thing, and all of them are opened when you open the pdf file to read it? I do not want this, I think you do too?