This doesn’t match what I’ve been told by multiple senior level support representatives. None of them are aware of any known issues with the Mail app and Yahoo Mail.
I’ve been dealing with Apple support for over a month. I was supposed to get another callback today (12/19) but for some reason I got an email about a missed call even though my phone never rang. I called in and got redirected to a different senior support agent.
He is not aware of any issues with Yahoo Mail in the Mail app in iOS 18.2. Neither was the original support agent.
He opened a RTA. The original agent told me she did that, but apparently never submitted any of the logs she collected to the engineers, so nothing has happened for a month. The new agent collected logs and said he’d submit them. Of note the Mail logging initiated by support is still broken. Any attempt to submit those logs immediately fails.