Mail authentication failed
I have a macbook pro Retina 15 in, operating on Mojave. Since last night I have been experiencing problems with my Mailbox. I have three e-mail accounts linked to my mailbox. Since yesterday I am constantly being asked to enter the password for two of these accounts (google and yahoo), but when I do I receive an error message saying Authentication Failed. There is no doubt that I am entering the correct password, since I can access my accounts normally from the browser. If I select the option to take all accounts online then the problem goes away, but it soon reappears.
Is there anyone else having a similar problem? What seems to be the reason for that?
MacBook Pro 15", macOS 10.14