This morning i have received an email from Craig who has suggested a very simple solution to enable proxy in GO Contact Sync. The trick is to created a config file GOContactSync.exe.config in installation directory and put this content in:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.net>
<defaultProxy enabled="true"
useDefaultCredentials="true">
<proxy bypassonlocal="true"
proxyaddress="http://proxy:80/" />
</defaultProxy>
</system.net>
</configuration>
Then replace "http://proxy:80/" with your proxy address. That's it.
Thanks, Craig!