It occurred to me that Chuck Swiger wrote in gmane.os.netbsd.help:
> If you're sending your own mail from a dynamic IP range, such as a DSL or 
> cable broadband pool, you will probably be better off relaying mail through 
> your ISP's designated mailserver.

Which you would be, regardlessly of the greylisting by the netbsd mailing-
lists, as many mailhosts will even *black*list you, just because you're
a dynamic IP.