If neither Mercury nor Outlook can connect to mail.site4test.x10.bz it's a networking problem rather than a Mercury problem. Make sure that login details for the server are entered correctly in MercuryC configuration and that port 25 isn't blocked by some firewall. To get more information you can try temporarily switching on session logging in MercuryC.

/Rolf 

Hello I am configuring it with my xampp mercury to send mail from my localhost to any mail like example@gmail.com. I am using this mail domain server mail.site4test.x10.bz but it doesn’t seems to work. I follow every instruction which this article wrote but it having problem on connecting to this outgoing mail server mail.site4test.x10.bz I have tried it on Outlook and the error is this.

ERROR: Send test e-mail message: Outlook cannot connect to your outgoing (SMTP) e-mail server. If you continue to receive this message, contact your server administrator or Internet service provider (ISP).