If you're using Windows Mail or similar on a PC, this should get you up and running:

Open your Vodafone account settings in the mail client.

Under the Servers tab make sure the setting is smtp2.vodafone.net.nz (as pointed out above) and the My server requires authentication checkbox is checked - the settings related to this should be Use same settings as my incoming mail server.  This will stop the requests for username/password.

In the Advanced tab, make sure the port for your outgoing mail server is set to 25 and the This server requires a secure connection (SSL) checkbox is unchecked.  Trying to connect securely will prevent your emails from sending.

It's a shame Vodafone don't post basic settings like this on their website.  They give you half the picture and you have to figure the rest out for yourself.  Having said that, they're not the only company like this, but that's hardly any sort of excuse...

Thanks for that it works now.

Just notice that my n82 keeps putting  my username and password in the outgoing mail server.I've deleted that part and it works now

Vodafone don't really give these basic settings which I agree .Hopefully things will improve