I have email redirected from other domains into my (Gmail) inbox. For it to arrive, I use SRS, so the email is properly aligned and always makes it into my inbox. The problem is that some of that email is malicious. I have a choice of dropping those mails, and I never see a trace of it in my inbox, or forwarding them with SRS, and they look to Gmail like 100% perfectly good mails sent from my own domain (but still potentially malicious). It's annoying.