This is log from dovecot 2.2.10:

2014-01-11T09:55:14+01:00 server/a.b.c.d dovecot: imap(user@domain): Error: Corrupted transaction log file /pracmail/domain/user/mail/.sent-mail/dovecot.index.log seq 16777216: log file shrank (868 < 6144) (sync_offset=6144) 2014-01-11T09:55:14+01:00 server/a.b.c.d dovecot: imap(user@domain): Panic: file buffer.c: line 307 (buffer_set_used_size): assertion failed: (used_size <= buf->alloc) 2014-01-11T09:55:14+01:00 server/a.b.c.d dovecot: imap(user@domain): Error: Raw backtrace: /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot.so.0(+0x6c2fa) [0x7f0704fa22fa] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot.so.0(+0x6c366) [0x7f0704fa2366] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot.so.0(i_error+0) [0x7f0704f5802f] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot.so.0(+0x67489) [0x7f0704f9d489] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0(mail_transaction_log_file_open+0x2c0) [0x7f07052ed120] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0(mail_transaction_log_open+0xb8) [0x7f07052e99b8] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0(+0xc1784) [0x7f07052cf784] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0(mail_index_open+0xf0) [0x7f07052cfac0] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0(index_storage_mailbox_open+0xac) [0x7f07052c0fac] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0(+0x4d43a) [0x7f070525b43a] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0(+0x4d50f) [0x7f070525b50f] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0(+0x84054) [0x7f0705292054] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0(mailbox_open+0xf) [0x7f070529220f] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0(index_storage_get_status+0x4a) [0x7f07052bfc2a] -> /usr/local/dovecot/lib/dovecot/lib10_quota_plugin.so(+0xb8ac) [0x7f0704d1c8ac] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0(mailbox_get_status+0x8c) [0x7f0705291ebc] -> dovecot/imap(imap_status_get+0x7a) [0x42058a] -> dovecot/imap(cmd_status+0x15d) [0x413a0d] -> dovecot/imap(command_exec+0x3d) [0x418acd] -> dovecot/imap() [0x417b10] -> dovecot/imap() [0x417c25] -> dovecot/imap(client_handle_input+0x125) [0x4180b5] -> dovecot/imap(client_input+0x6f) [0x41892f] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot.so.0(io_loop_call_io+0x36) [0x7f0704fb2c66] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot.so.0(io_loop_handler_run+0x95) [0x7f0704fb3fd5] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot.so.0(io_loop_run+0x38) [0x7f0704fb2bd8] -> /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot.so.0(master_service_run+0x13) [0x7f0704f5d483] -> dovecot/imap(main+0x2a7) [0x422807] 2014-01-11T09:55:14+01:00 server/a.b.c.d dovecot: imap(user@domain): Fatal: master: service(imap): child 25125 killed with signal 6 (core dumped) 2014-01-11T09:55:15+01:00 server/a.b.c.d dovecot: imap(user@domain): Error: Transaction log file /pracmail/us.edu.pl/user/mail/.sent-mail/dovecot.index.log: marked corrupted

Unfortunately I'm not able to find core file although 'core dumped' is written to the log.

MU