[Exim] exim4 recipient verify .forward filter local_part_suf…

I'm beginning the process of moving a number of exim3 servers to exim4.

I'm only having one small problem on my test platform.

My configuration file is VERY basic - just out of the box.

I have added:

local_part_suffix = -*
local_part_suffix_optional
allow_filter

to the userforward router.

Everything works fine locally (non-smtp)

mail -s test user-validsuffix@??? </dev/null works fine

mail -s test user-invalidsuffix@??? </dev/null is accepted but
returned

mail from remote hosts across tcp/ip is "550 user unknown" for both
addresses.

exim4 -bt is successful

exim4 -bv fails

I assume setting "verify_recipient" will allow the traffic. If I'm wrong,
please correct me.

My real question. Why is no_verify set to begin with? Why are no_verify
and no_expn set in the procmail router?

What "holes" am I opening by changing this setting? What is the performance
hit on a busy server?

-Jeff