one way is to have a site that u own where the program is checking for updates, like
http://mysite.com/ver

u make your program download "ver" that is a simple txt file, like

<version>
1.01
</version>
<changelog>
1.01 bugfix: arrow now working
1.00 first version
</changelog>
<message>
hello, its time for a new update
if you enjoy this program, check my website for more info and updates
</message>
<website>
http://mynewsite.com/index.html
</site>
<versionsite>
http://mynewsite.com/ver
</versionsite>

well u get it,
that way, when a new update is available, u create a popup message when the user start the program, about new updates
u can make the update automatically if u wish or manually, if u tell the user to go to the site.

to have email communication is just a mess.