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 'Password, transmitted insecurely'. If it used to work but now doesn't, you may be susceptible to getting your password stolen.
Zda so, zo wuchadny serwer (SMTP) %S zaklučowane hesła njepodpěruje. Jeli runje konto konfigurujeće, spytajće 'awtentifikacisku metodu' w 'Kontowe nastajenja | Wuchadny serwer (SMTP)' do 'Hesło, njewěsće přenjesene' změnić. Jeli to zwjetša funguje, ale nětko nic, je móžno, zo so waše hesło kradnje.