OK, as far as I can find that error is authentication is required. There is something wrong with your authentication ether it is not checked or name and password in not correct.
The error numbers are comming from the stmp server. The server does not like what it is getting from the NET module. Recheck email addresses and username and password. At this time I don't have a way to hook up my NET module to try anything.
I might have found something if you have a gmail account. You can send non ssl emails to a gmail account from a gmail account. With aspmx.l.google.com using your current email account. Use port 25. No authentication required. Remember you will have to send it to your gmail account for it to work.
That is the stmp server name. Both the to and from email would be your gmail address. Basically you will be emailing yourself. It said authentication not required, so I don't think it reqiures the login info. Uncheck the box and see.