Anonymous email users

I notice that in some recent discussions, we have users who cannot be
replied to directly as their email addresses are not valid ones, and I
believe on purpose. Examples in the thread I was going to reply to are:
 
 <mailto:HenHanna@devnull.tb> HenHanna@devnull.tb
 
 <mailto:no.email@nospam.invalid> no.email@nospam.invalid
 
 <mailto:candycanearter07@candycanearter07.nomail.afraid>
candycanearter07@candycanearter07.nomail.afraid (user <candycane> is
generated from /dev/urandom)
 
I know some here suggest that we only reply to the wider community and they
have a point. But I think there is a role for having some conversations
offline and especially when they are not likely to be wanted, or even
tolerated, by many in the community.
 
Using such fake or invalid emails makes it hard to answer the person
directly or perhaps politely ask them for more info on their request or
discuss unrelated common interests. Worse, when I reply, unless I use
reply-all, my mailer sends to them futilely. When I do the reply-all, I have
to edit out their name or get a rejection.
 
I understand some are concerned over getting email of the junk variety by
any who scan members of forums like this. I can see making a throwaway email
address for such purposes that can be replaced when it gets inundated. But
emails that don't work are a bit irksome to me albeit I assume perfectly
legit for many purposes.
 
The thread I posted in recently is an example where I spent a little time,
just for fun, and wrote a fairly short piece of code (almost a one-liner)
that I might have sent to the OP and not bothered others here with. I
suspect few here understand why there was a request to generate a limited
subset of three-digit numbers. I did suggest an outline of a way it could be
done, perhaps a bit wastefully but compactly. But there is no way to share
that with people who choose not to receive private email except to post
something like this here:
 
import re
[i for i in range(999) if re.match("^[1-4]0[1-3]$",str(i))]
 
* The internet is a wild place and when it is anonymous, even wilder.