i found this on godaddy.com:
“Yes! Finally after calling technical support I was able to get a fix!
The problem was not anything I was doing, rather something that needed to be addressed on the godaddy side. Not something I could have done myself.
the problem stemmed from a setting for the “key” which allows you to send from a third party email client being “locked”. Would have happened if I was trying to use outlook or any other program of the sort.
my advise would be to call tech support and have them analyze the settings of your account. If its the same thing, it was fixed in one short 5 minute phone call.”
Here is the url: