Seems to be related to https://bugzilla.redhat.com/show_bug.cgi?id=1189198 https://bugzilla.redhat.com/show_bug.cgi?id=1189198. Separate note the link to Overview of all dovecot.org mailing lists http://dovecot.org/mailman/listinfo http://dovecot.org/mailman/listinfo http://dovecot.org/mailman/listinfo is broken as are the images on the page.

Here’s the backtrace.

dovecot[12438]: imap(username): Error: Raw backtrace: /usr/lib64/dovecot/libdovecot.so.0(+0x91ab2) [0x7ff01e98cab2] -> /usr/lib64/dovecot/libdovecot.so.0(+0x91bad) [0x7ff01e98cbad] -> /usr/lib64/dovecot/libdovecot.so.0(i_fatal+0) [0x7ff01e925f41] -> /usr/lib64/dovecot/libdovecot-storage.so.0(+0xaa1ed) [0x7ff01ecc01ed] -> /usr/lib64/dovecot/libdovecot-storage.so.0(index_mail_get_first_header+0xd2) [0x7ff01ecc0652] -> /usr/lib64/dovecot/libdovecot-storage.so.0(mail_get_first_header+0x3d) [0x7ff01ec4c88d] -> /usr/lib64/dovecot/libdovecot-storage.so.0(+0xbe717) [0x7ff01ecd4717] -> /usr/lib64/dovecot/libdovecot-storage.so.0(+0xbe952) [0x7ff01ecd4952] -> /usr/lib64/dovecot/libdovecot.so.0(i_stream_read+0x53) [0x7ff01e997653] -> /usr/lib64/dovecot/libdovecot.so.0(i_stream_read_data+0x3d) [0x7ff01e99807d] -> /usr/lib64/dovecot/libdovecot.so.0(message_parse_header_next+0x72) [0x7ff01e9748e2] -> /usr/lib64/dovecot/libdovecot.so.0(+0x73d91) [0x7ff01e96ed91] -> /usr/lib64/dovecot/libdovecot.so.0(i_stream_read+0x53) [0x7ff01e997653] -> /usr/lib64/dovecot/libdovecot.so.0(i_stream_read_data+0x3d) [0x7ff01e99807d] -> /usr/lib64/dovecot/libdovecot.so.0(message_parse_header_next+0x72) [0x7ff01e9748e2] -> /usr/lib64/dovecot/libdovecot.so.0(message_parse_header+0x4f) [0x7ff01e97527f] -> /usr/lib64/dovecot/libdovecot-storage.so.0(+0xb0d4b) [0x7ff01ecc6d4b] -> /usr/lib64/dovecot/libdovecot-storage.so.0(+0xb2e63) [0x7ff01ecc8e63] -> /usr/lib64/dovecot/libdovecot-storage.so.0(index_storage_search_next_nonblock+0x114) [0x7ff01ecc9574] -> /usr/lib64/dovecot/libdovecot-storage.so.0(mailbox_search_next_nonblock+0x22) [0x7ff01ec56d52] -> dovecot/imap(+0x221ff) [0x559b559541ff] -> dovecot/imap(imap_search_start+0xd1) [0x559b559545c1] -> dovecot/imap(cmd_search+0xd3) [0x559b55946063] -> dovecot/imap(command_exec+0xa5) [0x559b5594d5d5] -> dovecot/imap(+0x19852) [0x559b5594b852] -> dovecot/imap(+0x198de) [0x559b5594b8de] -> dovecot/imap(client_handle_input+0x1b5) [0x559b5594bce5] -> dovecot/imap(client_input+0x82) [0x559b5594c262]

dovecot[12438]: imap(username): Error: Raw backtrace: /usr/lib64/dovecot/libdovecot.so.0(+0x91ab2) [0x7f77a0cd7ab2] -> /usr/lib64/dovecot/libdovecot.so.0(+0x91bad) [0x7f77a0cd7bad] -> /usr/lib64/dovecot/libdovecot.so.0(i_fatal+0) [0x7f77a0c70f41] -> /usr/lib64/dovecot/libdovecot-storage.so.0(+0xaa1ed) [0x7f77a100b1ed] -> /usr/lib64/dovecot/libdovecot-storage.so.0(index_mail_get_first_header+0xd2) [0x7f77a100b652] -> /usr/lib64/dovecot/libdovecot-storage.so.0(mail_get_first_header+0x3d) [0x7f77a0f9788d] -> /usr/lib64/dovecot/libdovecot-storage.so.0(+0xbe717) [0x7f77a101f717] -> /usr/lib64/dovecot/libdovecot-storage.so.0(+0xbe952) [0x7f77a101f952] -> /usr/lib64/dovecot/libdovecot.so.0(i_stream_read+0x53) [0x7f77a0ce2653] -> /usr/lib64/dovecot/libdovecot.so.0(i_stream_read_data+0x3d) [0x7f77a0ce307d] -> /usr/lib64/dovecot/libdovecot.so.0(message_parse_header_next+0x72) [0x7f77a0cbf8e2] -> /usr/lib64/dovecot/libdovecot.so.0(+0x73d91) [0x7f77a0cb9d91] -> /usr/lib64/dovecot/libdovecot.so.0(i_stream_read+0x53) [0x7f77a0ce2653] -> /usr/lib64/dovecot/libdovecot.so.0(i_stream_read_data+0x3d) [0x7f77a0ce307d] -> /usr/lib64/dovecot/libdovecot.so.0(message_parse_header_next+0x72) [0x7f77a0cbf8e2] -> /usr/lib64/dovecot/libdovecot.so.0(message_parse_header+0x4f) [0x7f77a0cc027f] -> /usr/lib64/dovecot/libdovecot-storage.so.0(+0xb0d4b) [0x7f77a1011d4b] -> /usr/lib64/dovecot/libdovecot-storage.so.0(+0xb2e63) [0x7f77a1013e63] -> /usr/lib64/dovecot/libdovecot-storage.so.0(index_storage_search_next_nonblock+0x114) [0x7f77a1014574] -> /usr/lib64/dovecot/libdovecot-storage.so.0(mailbox_search_next_nonblock+0x22) [0x7f77a0fa1d52] -> dovecot/imap(+0x221ff) [0x563492d1d1ff] -> dovecot/imap(imap_search_start+0xd1) [0x563492d1d5c1] -> dovecot/imap(cmd_search+0xd3) [0x563492d0f063] -> dovecot/imap(command_exec+0xa5) [0x563492d165d5] -> dovecot/imap(+0x19852) [0x563492d14852] -> dovecot/imap(+0x198de) [0x563492d148de] -> dovecot/imap(client_handle_input+0x1b5) [0x563492d14ce5] -> dovecot/imap(client_input+0x82) [0x563492d15262]

dovecot --version 2.2.26.0 (23d1de6)

dovecot -n # 2.2.26.0 (23d1de6): /etc/dovecot/dovecot.conf # OS: Linux 4.8.4-200.fc24.x86_64 x86_64 Fedora release 24 (Twenty Four) mail_fsync = always mail_location = mbox:~/mail:INBOX=/var/spool/mail/%u mail_nfs_index = yes mail_nfs_storage = yes mbox_write_locks = fcntl mmap_disable = yes namespace inbox { inbox = yes location = mailbox Drafts { special_use = \Drafts } mailbox Junk { special_use = \Junk } mailbox Sent { special_use = \Sent } mailbox "Sent Messages" { special_use = \Sent } mailbox Trash { special_use = \Trash } prefix = } passdb { driver = pam } ssl = required ssl_cert =