There's no need to create an extra account for something like that, you set the From header to whatever you like and it would be best to leave the Reply-To empty.
One thing though.
It's against the technical specifications of the net to use a From address that you don't own. There are providers that ban you from their customer base for that. Those specs date from before the war against spam, but since that's going on those rules are enforced more than before.
Therefore the use of a noreply@something_domain should only be used when you own that specific address at that domain or when you own the domain itself, so you can garantuee that nobody else will own that address as long as you're using it.