> What is the advantage of bothering to do this? For SMTP: log optimization. Like: yeah, I don't care that you're self-DDOSing if you're an actual spammer. Bu

> What is the advantage of bothering to do this? For SMTP: log optimization. Like: yeah, I don't care that you're self-DDOSing if you're an actual spammer. But, just in case you're a legitimate sender lacking SPF records, and you just need some help, I still want some kind of signal. For SSH, I guess you might want something similar, just to catch authorized-yet-misconfigured remotes...