Windows Live Mail

I am using Widows Live Mail and Widows 7.

I can receive emails, but cannot send them.

The error message is as follows:

An unknown error has occurred

Server: "send.xtra.co.nz

Windows Live Mail error ID: 0x8007007A
Protocol: SMTP
Port: 465
Secure (SSL): Yes

I had this problem before. Hopefully someone can help me.

Gerrit