If using CDOSYS with Universal Email works without an error message, the it should also work in the security Assist Email Password behavior. I dont think the email object is causing the 500 server error.
A 500 server error is a generic error, it just means "An error occurred", it's not very helpful for trouble shooting.
if your using IE, there is a Show friendly http error messages setting that will cause it to show a 500 error instead of the real error. got to Internet Options -> Advanced and uncheck the show friendly http errors if you are using IE.
if you are not using IE, and still getting the 500 error, it is difficult to know what the problem is. try contacting GoDaddy to see if they can either set the server to display the real error, or look into the error logs and let you know what the real error is.
We need to know the actual error that is occurring to be able to trouble shoot.