Hi.
When a user is over quota and a message is rejected, it sends a message back changing partially the subject (depending on the size).
With utf-8 it breaks the information, we noticed this behavior when the subject line uses utf-8 and it is broken in more than one line:
Subject: Quêm casé erat vim id, vix ín dicit putânt, minim çónsequuntur ea iús. Agam cetêro tê eôs, ád vim ipsum tantâs expetêndis. Ut prõ vidit diçit iudicabit, cum út çômmódo
Subject of a delivered message: Subject: =?UTF-8?Q?Qu=C3=AAm_cas=C3=A9_erat_vim_id=2C_vix_=C3=ADn_dicit_p?= =?UTF-8?Q?ut=C3=A2nt=2C_minim_=C3=A7=C3=B3nsequuntur_ea_i=C3=BAs=2E_Agam_?= =?UTF-8?Q?cet=C3=AAro_t=C3=AA_e=C3=B4s=2C_=C3=A1d_vim_ipsum_tant=C3=A2s_e?= =?UTF-8?Q?xpet=C3=AAndis=2E_Ut_pr=C3=B5_vidit_di=C3=A7it_iudicabit=2C_cum?= =?UTF-8?Q?_=C3=BAt_=C3=A7=C3=B4mm=C3=B3do?=
Subject of a message rejected with Dovecot Quota: Subject: Rejected: =?UTF-8?Q?Qu=C3=AAm_cas=C3=A9_erat_vim_id=2C_vix_=C3=ADn_dicit_p?=? =?... Auto-Submitted: auto-replied (rejected) Precedence: bulk
https://pastebin.com/raw/SWJJARga
Regards.
Danilo G. Baio (dbaio)