Hi, In my server, accounts are receiving many doubled emails in its mailbox. In some accounts the "doveadm deduplicate" is doing nothing, even if there are duplicate messages. But in some cases, this error has left me particularly concerned: # doveadm deduplicate -u <user> -m ALL doveadm(<user>): Panic: file mail-transaction-log.c: line 271 (mail_transaction_log_rotate): assertion failed: (file->locked) doveadm(<user>): Error: Raw backtrace: /usr/lib/dovecot/libdovecot.so.0(+0x67f30) [0x7f77b9f85f30] -> /usr/lib/dovecot/libdovecot.so.0(default_fatal_handler+0x2a) [0x7f77b9f85f9a] -> /usr/lib/dovecot/libdovecot.so.0(i_fatal+0) [0x7f77b9f39515] -> /usr/lib/dovecot/libdovecot-storage.so.0(+0xc296f) [0x7f77ba2b996f] -> /usr/lib/dovecot/libdovecot-storage.so.0(mail_index_write+0x1be) [0x7f77ba2b8c3e] -> /usr/lib/dovecot/libdovecot-storage.so.0(mail_index_sync_commit+0x262) [0x7f77ba2b1012] -> /usr/lib/dovecot/libdovecot-storage.so.0(mdbox_map_atomic_finish+0x26) [0x7f77ba225a36] -> /usr/lib/dovecot/libdovecot-storage.so.0(mdbox_sync+0x61) [0x7f77ba229d91] -> /usr/lib/dovecot/libdovecot-storage.so.0(mdbox_storage_sync_init+0x66) [0x7f77ba229e26] -> /usr/lib/dovecot/libdovecot-storage.so.0(mailbox_sync_init+0x2b) [0x7f77ba26954b] -> /usr/lib/dovecot/libdovecot-storage.so.0(mailbox_sync+0x27) [0x7f77ba269657] -> doveadm(+0x1b5f4) [0x7f77bab995f4] -> doveadm(+0x1970b) [0x7f77bab9770b] -> doveadm(doveadm_mail_try_run+0x26c) [0x7f77bab9845c] -> doveadm(main+0x414) [0x7f77bab946a4] -> /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf5) [0x7f77b9b7aec5] -> doveadm(+0x168f7) [0x7f77bab948f7] I'm using dovecot-2.2.15. Is this known? What other kind of information could be useful to help find this issue? Full log on the link: http://pastebin.com/CMfjxydy My confs with doveconf -n : http://www.adminlinux.com.br/newcluster_doveconf.txt Thanks Thiago Henrique