When you want to block an email address which one would be more effective? To black list the email address in the local.cf file for SA? Or the badmailfrom for qmail? Or do you suggest putting them in both?
badmailfrom.
If you're going to block an address outright, it much better to just do it by making the SMTP layer do a 5xx error.
If you do it at the SA layer, the message will have to be received, and fed to SA before anything can be done about it. However the badmailfrom will happen before the message body is even sent. You save CPU time and network bandwidth if you avoid the SA call.
