I have AOL, not yahoo, but I think the same applies. I don't THINK you had to delete your email account. It's really strange. If you open the account settings under outlook I do not see a way to change the server info. BUT go into control panel... may be a little different if you open control panel directly but I go thru the menu and it's user accounts, then mail (microsoft outlook). From there choose email accounts.
It opens something that looks exactly the same as from within outlook except that change has the server URLs, user name and password. And under more settings on the advanced tab they have the ports and some other settings.
Haven't tried; I'd have to dig up the info on app passwords in case I need to change that if I use a different server. We only change the income server, right?
(I think I have an email on how to set up the app password, but it might be more than 10,000 emails away! I can do one of my rare logins to actual AOL and search for app passwords I guess. JUST to be prepared; I seem to recall I was able to copy from one device to another... that may have been android, as I don't see a way in outlook to display it.
I more or less found this from:
https://support.microsoft.com/en-us/office/change-or-update-email-account-settings-in-outlook-for-windows-560a9065-3c3a-4ec5-a24f-cdb9a8d622a2
Which I got from help in the account settings and searched for reset mail settings. I did that because that was on a button in the ouitlook change. I did NOT want to hit the button only to find that it reset all my settings! The help did NOT address that button in outlook but covered the additional detail in the control panel one. If anyone is brave enough to clock on that reset button from outlook let us know, but I don't need it; I can easily do it from control panel. Just need to wait until I can dig up or search AOL to know how to change the app password, in case I need it.
I found it (thru control panel) in Outlook 2016 in WIn7 and it also looked the same in Outlook 2021 in Win10. As I said, didn't change it and won't until I can generate the app password if needed. (I thought I read somewhere that app passwords weren't needed anymore.)