Re: [Nmh-workers] Message-IDs and Content-IDs

[Tom Lane]

David Levine <address@hidden> writes:
> Non-qualified hostnames do get used, even to this list.  I
> looked at a small collection of spam and saw hardly any
> random "hostname" parts, but the sample is biased (it got
> through some filters) and very small.

I have a rather larger collection of spam handy ... and there's
quite a lot of unqualified hostnames in there, as well as quite
a lot of raw IP addresses.

I would suggest trying to make sure that the phony-hostname part
doesn't look like either of those categories.  I don't personally
use such a thing as spam sign, but I bet some people do.  Perhaps
it would do to intentionally insert a couple of dots in the otherwise
random string, ie instead of "address@hidden" something like
"address@hidden".

Personally I'd be inclined to limit the characters used for the "random"
data to alphanumerics, too, to make it look more like a hostname.
If you want 64 characters so that it works like base64, maybe add "-"
and "_" to the repertoire.

                        regards, tom lane