Received from Shal Farley at 3/18/2019 08:04 AM UTC:
the number of yahoo members who are bouncing is increasing unfortunately. woke up this morning to over 150...
That could be a delayed reaction to an outage on 3/15. But I don't see how that could account for the surge on 3/8.
You haven't told us what the affected member's Email Delivery History has to say.
In my groups it started about Mar 8 and accelerated on Mar 12.
The Email Deliver History says, "554 delivery error: dd Sorry, your message to XXXXXX@... cannot be delivered. This mailbox is disabled (554.30). - mta4486.mail.gq1.yahoo.com"
Jim H