Ah, another day full of Microsoft joy.
Months ago: $DAYJOB disabled access to standard IMAP/SMTP clients, limiting only to approved UA IDs via OAUTH2. So no mutt/neomutt, no OfflineImap/mbsync, no Claws, and no Thunderbird. Just the Outlook thick-client and the web-client. Fine, so I'll use the thick-client.
A month or three ago: some upgrade happened breaking the Outlook thick client. Their only options were upgrading the OS on the VM (to support the latest Outlook thick-client) or using the web interface. They didn't upgrade the VM, so I'm stuck with the unbearable web interface.
Today: I go to log into the webmail interface, and the SSO server web interface is down preventing me from reading or sending *any* email. Including what would have been cached offline by any of the above clients.
Meanwhile, my personal IMAP/SMTP server? still provides access from any CLI, GUI, sync-utility, or web client I set up. My MUA allows for offline access, so at least I can compose replies and queue them up if things go offline. Sigh.
I guess it's time to find something other than work to do.