I read the MOTD of the previous day that webmail was having problems. I exclusively use shell mail. I do not use Webmail since it is an imprecise management tool; previous problems with webmail didn't seem to affect shell mail for my accounts. But since yesterday, my shell account is missing hundreds (no exaggeration there) of expected mails. Google is showing that I can do administrative commands for various forum for which I am responsible (so I know it isn't a listserv problem.) Mails from all lists, including yahoo forums have ceased to come to my sonic folders. I am also missing receipts for Amazon purchases handled on an alt sonic.net account. I haven't seen discussion of this problem anywhere and nntp via tin seems to be gone.
Mail trickle didn't have a defined pattern. I started to wonder if my procmail recipe has an error since my folder recipes are further down my procmailrc-first.
I decided to disable my procmail-first for the time and mail is coming in, unsorted.
Previous MOTD mention of changes for shell folders of various ref programs was noted some time ago, but there had been no changes is mail behavior until yesterday. I think I have found the probable source of my mail problem.