The IMAP server %S does not seem to support encrypted passwords. If you just set up the account, please try changing to 'Password, transmitted insecurely' as the 'Authentication method' in the 'Account Settings | Server settings'. If it used to work and now suddenly fails, this is a common scenario how someone could steal your password.
Aqeddac  IMAP %S ur yessefrak ara awalen uffiren iwgelhanen. Ma yella tura kan i yettusbadu, snifel-it ɣer 'Awal uffir, yettwazen s wudem araɣelsan' am 'Tarray n isesteb' deg 'Iɣewwaṛen n umiḍan | Iɣewwaṛen n uqeddac'. Ma yella iteddu yakan sakin yuɣal yeḥbes, d asinaryu yettwasnen n takerḍa n wawalen uffiren.