This POP3 server 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  POP3 ur yessefrak ara awalen uffiren iwgelhanen. Ma yella tura kan i yettusbadu, snifel-it ɣer 'Awal uffir, yettwazen s wudem araɣelsan' am 'Tarray n usesteb' deg 'Iɣewwaṛen n umiḍan | Iɣewwaṛen n uqeddac'. Ma yella iteddu yakan sakin yuɣal yeḥbes, d asinaryu yettwasnen n takerḍa n wawalen uffiren.