iPhone cannot verify e-mail server identity

It seems that every three months, when a mail server automatically renews it's Let's Encrypt SSL certificate, (if so equipped) Apple will no longer allow outbound e-mail to be sent. Users get a message that reads, "cannot verify server identity". The new certificate is valid, of course.

I've found this old thread: iPhone cannot verify server identity - Apple Community

I am amazed that the solutions offered all basically boil down to "delete the account, power cycle the iPhone (or iPad) and set it up again".

On what planet is this a good long term solution? Imagine having an organization of a few hundred people, that all love their Apple devices, that have to delete and set up their email account on their iPhone and their iPad every three months. Imagine providing hours and hours of I.T. support for those folks. Imagine all of the lost time and productivity. Imagine all these people getting ****** off, "why does this keep happening?"

This appears to me, to be an issue between Apple and "Let's Encrypt". Why does the "continue" not appear unless the account is deleted and set up again? How is that not an Apple bug? It worked fine before the certificate renewal. It still works fine on Microsoft devices. The certificate is will fly after the account is deleted and set up again, but otherwise Apple doesn't like it? As Col. Potter would say, "Horse Hockey!!"

How about a real solution, not a band aid that's good for three months.