The Outgoing server (SMTP) %S does not seem to support encrypted passwords. If you just set up the account, try changing the 'Authentication method' in 'Account settings | Outgoing server (SMTP)' to 'Normal password'.
Zda so, zo wuchadny serwer (SMTP) %S zaklučowane hesła njepodpěruje. Jeli runje konto konfigurujeće, spytajće 'awtentifikacisku metodu' w 'Kontowe nastajenja | Wuchadny serwer (SMTP)' do 'Normalne hesło' změnić.