On Sun, Mar 19, 2023 at 06:38:41PM +0800, coreyh@free.fr wrote: > So, > > * 188.66.63.1/24 is a range, not a single host in SPF > * why it's not written as 188.66.63.0/24 which is more clear? Because it was written by a human being who made a tiny error. One that makes no difference in practice.