>/24 netblock on the second offense.
That seems excessive and abusive, I am not aware of any commercial ISP that is giving out /24 anymore. /29 is most common, I had to practically beg to get a /28 so what is the justification for banning an /24???
That seems excessive and abusive, I am not aware of any commercial ISP that is giving out /24 anymore. /29 is most common, I had to practically beg to get a /28 so what is the justification for banning an /24???
If they did, what would be Google's justification for blocking senders that send too few emails?
Good thing it's my own mail server then, isn't it?
The practical reason is that virtually all Whois lookups of offending IPs return blocks of /24 or larger, so that's a reasonable default. Besides, as I said, this doesn't result in a "ban", just tags emails as spam and passes them through. At my scale an occasional false positive is not a big deal.