I have two computers using High Sierra (this was not intentioanl either that is another story). The email settings are wrong on one comptuer & nothing I do can seem to fix the IMAP & SMTP settings; while on the other computer the same settings work. I am typing in the correct settings & I then I get an error message "unable to verify account name or password". The computer with problems is an older device & thus may have a differnt keychain. They are using the same iCloud account for keychain sharing.
Is there a way I can possibly clean the key chain & get the keychain to re-sychronize across devices?