This is log from dovecot 2.2.10:

2014-01-13T15:34:39+01:00 server/a.b.c.d dovecot: imap(user@domain): Fatal: master: service(imap): child 6290 killed with signal 11 (core dumped)

(gdb) bt full #0 0x00007fe78683aba5 in mail_cache_header_fields_read () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0 No symbol table info available. #1 0x00007fe78683890a in mail_cache_open_and_verify () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0 No symbol table info available. #2 0x00007fe78683c339 in mail_cache_field_exists () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0 No symbol table info available. #3 0x00007fe78683c459 in mail_cache_lookup_field () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0 No symbol table info available. #4 0x00007fe786821949 in index_mail_cache_lookup_field () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0 No symbol table info available. #5 0x00007fe7868222d6 in index_mail_update_access_parts () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0 No symbol table info available. #6 0x00007fe786822676 in index_mail_set_seq () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0 No symbol table info available. #7 0x00007fe786829f51 in search_more () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0 ---Type <return> to continue, or q <return> to quit--- No symbol table info available. #8 0x00007fe78682a778 in index_storage_search_next_nonblock () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0 No symbol table info available. #9 0x00007fe786800257 in mailbox_search_next_nonblock () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0 No symbol table info available. #10 0x00007fe7868002b6 in mailbox_search_next () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot-storage.so.0 No symbol table info available. #11 0x000000000041b637 in imap_fetch_more_int () No symbol table info available. #12 0x000000000041b871 in imap_fetch_more () No symbol table info available. #13 0x000000000040d8ae in cmd_fetch () No symbol table info available. #14 0x0000000000418acd in command_exec () No symbol table info available. #15 0x0000000000417b10 in client_command_input () No symbol table info available. #16 0x0000000000417c25 in client_command_input () No symbol table info available. #17 0x00000000004180b5 in client_handle_input () ---Type <return> to continue, or q <return> to quit--- No symbol table info available. #18 0x000000000041892f in client_input () No symbol table info available. #19 0x00007fe786522c66 in io_loop_call_io () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot.so.0 No symbol table info available. #20 0x00007fe786523fd5 in io_loop_handler_run () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot.so.0 No symbol table info available. #21 0x00007fe786522bd8 in io_loop_run () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot.so.0 No symbol table info available. #22 0x00007fe7864cd483 in master_service_run () from /usr/local/dovecot-2.2.10/lib/dovecot/libdovecot.so.0 No symbol table info available. #23 0x0000000000422807 in main () No symbol table info available. (gdb)

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