Diversion E-mail from Diversion when sending via Yahoo suddenly does not work !!!

[Twiglets]

I have been using the auto-backup feature of diversion to send 'Router Backup (Key-files)' automagically for years.
Suddenly they are being bounced by Yahoo.

I'm afraid I wasn't able to deliver the following message.
This is a permanent error; I've given up. Sorry it didn't work out.

Subject: ASUS_01 Router Backup (Key-files) 2026-03-08_08.50
To: [email protected]

The Test mail option in AMTM works !!!
The mail from BACKUPMON works !!!
They all use the same files in /jffs/addons/amtm/mail/ for username/password etc.

Help !!!!