Spam and 554 Errors

[netesq]

I recently started hosting some of my domains at BlueHost, and I set up one of them to use BlueHost as an e-mail host. Everything seems to be going fine, but I am getting a significant number of failure notices from the MAILER-DAEMON for e-mail messages that I didn't send, and I'm curious about the nature of these messages. Does BlueHost somehow prevent third parties from spoofing e-mail headers?

[netesq]

I did a little research on the issue I reported above, and I discovered that BlueHost e-mail is blocked by Barracuda Reputation. This was not the case with my previous hosting service for the domain in question. Consequently, I received copies of e-mails that were bouncing because they were purportedly from me as well as being addressed to me, even though I never sent them. Normally, I would be concerned that my hosting service had been blocked as a source of spam, but this state of affairs is actually a plus for me, as I don't actually send e-mails from the domain in question, and the spammers who are spoofing my return address are not reaching as many targets. Meanwhile, I am using Google Apps to send e-mail from my other domains, and those e-mails are getting through just fine.