Re: mail admins? Proposal of solution

[Denys Fedoryshchenko <nuclearcat () nuclearcat com>]

On 2020-04-30 02:43, Mark Andrews wrote:
> And it is still on going.  Just got 4 of these.
>
> Mark
Technical proposal how to solve that.

At 1st of month send monthly reminder manually, to each subscriber, but 
encode recipient address in Reply-To: a bit special way.
First, you need catch-all alias on special domain.
Then, you calculate reply-to, for example if destination recipient:
hash("secret-keyword" + user () domain com)=aabbccdd
So, it becomes:
Reply-To: aabbccdd () monthly nanog org

Then just check all bounces received to *@monthly.nanog.org, and 
unsubscribe relevant users.