iSeries Navigator Spam blocking?

Hi all,
I've been trying to block just 1, yes just one, spammer.  This is the most
prolific and dumbest spammer I've seen, with apparently two complete class b
sets of IP addresses.  They keep changing...(69.6.49.x) and (69.6.50.x).

This really stupid spammer keeps sending me about 10-20+ emails per day (on
a few email addresses) of non-compliant (malformed?) emails to my AS400 smtp
server using Outlook as client.  The emails from "him" ALWAYS jam up my
Outlook client and I have to go find the email(s) and delete them before I
can download successfully.

I say really (really, really) stupid because I don't ever even see the
message since I can't download it.  I've had IBM on this for a long time
(SEVERAL PMR's) and they can't fix it, even with dozens of examples and 2 or
3 smtp traces.

Anyway, is there some way I can block the emails originating from
(69.6.49.x) and (69.6.50.x) ip addresses?  I'm trying to enter them in the
"connection restrictions" panel in OpsNav.  As long as I enter the complete
email address (hundreds of them), it works.

Is there some way I can block the entire range of 69.6.49.x and 69.6.50.x?
I think I should be able to, but I'm apparently not getting the ip/subnet
length parms right.

It's getting really old having to manually delete the email (on the AS400)
and add the individual IP address to the "Connections Restrictions" panel.
So far, I've entered over a hundred IP addresses and it just keeps coming,
each time with a different low-order octet (my terminology may not be
right?) and domain name.  Wouldn't be so bad except that it hangs up my
email downloads and I have to manually find and delete the offending email.
This is going to get anything but better as Christmas comes up, I'm sure.

Your help is appreciated.  If there's any useful documentation on this, I
really don't mind reading it, but I have not found any yet (and I've
looked).

TIA

AS/Resources, Inc.
William A.(Tony) Corbett
IBM Certified Specialist - AS/400 Developer
http://www.asresources.com
corbett@xxxxxxxxxxxxxxx
770-587-9139 (office)
404-784-4737 (mobile)
fax:  678-935-5005