Mail can not verify account name or password

So all of a sudden, my mail app started behaving badly. I have a total of 5 email accounts hooked up, and on one server, I am reaching a dead end.

I had difficulty setting up the account, so I did a system update to High Sierra and I was allowed to enter the info, and the mail app connected to the server. However today, I had the ! triangle back, and my issue did not get resolved. When I went to uncheck on the automatically detect settings, and noticed my set up method of password was replaced with ND5 challenge. Now no matter what I do, I can not get past the the save, I always get unable to verify account name or password.

My server setting is quite simple. I am trying to log in with an easy setting IMAP on port 143 not using SSL. I am able to log in via the webmail interface. Oh and my iPhone access also broke, so it seems like my mail program can not access my keychain anymore.

Yes I tried everything.

Deleted info in keychain

Deleted and rebuilt account

Removed com.apple.mail from library

Any thoughts.