I'm using release 2.2.12, during a copy operation i get segfault on imap process. I have full bt of the issue: (gdb) bt #0 0x00007fcc521029cd in mail_cache_header_fields_read (cache=0x15c7210) at mail-cache-fields.c:369 #1 0x00007fcc52100664 in mail_cache_open_and_verify (cache=0x15c7210) at mail-cache.c:497 #2 0x00007fcc5210244d in mail_cache_register_get_list (cache=0x15c7210, pool=0x1573608, count_r=0x7fff7b3b2418) at mail-cache-fields.c:194 #3 0x00007fcc520ef845 in index_mail_parse_header_register_all_wanted (mail=0x15d4b60, headers=<value optimized out>) at index-mail-headers.c:170 #4 index_mail_parse_header_init (mail=0x15d4b60, headers=<value optimized out>) at index-mail-headers.c:230 #5 0x00007fcc520efdb8 in index_mail_cache_parse_init (_mail=0x15d4b60, input=0x15ddb38) at index-mail-headers.c:376 #6 0x00007fcc520bb163 in maildir_save_add (_ctx=0x15d3b20, tmp_fname=0x15735e8 "1392731650.M182940P5176.pecpop5", src_mail=0x0) at maildir-save.c:225 #7 0x00007fcc520bb4b8 in maildir_save_begin (_ctx=0x15d3b20, input=0x15debb8) at maildir-save.c:415 #8 0x00007fcc511e7360 in quota_save_begin (ctx=0x15d3b20, input=0x15debb8) at quota-storage.c:274 #9 0x00007fcc520cc182 in mailbox_save_begin (ctx=0x7fff7b3b25a8, input=0x15debb8) at mail-storage.c:2025 #10 0x00007fcc520c6242 in mail_storage_try_copy (ctx=0x15d3b20, mail=<value optimized out>) at mail-copy.c:76 #11 mail_storage_copy (ctx=0x15d3b20, mail=<value optimized out>) at mail-copy.c:101 #12 0x00007fcc520b6916 in maildir_copy (ctx=0x15d3b20, mail=0x15cf300) at maildir-copy.c:148 #13 0x00007fcc50dd7461 in notify_copy (ctx=0x15d3b20, mail=0x15cf300) at notify-storage.c:107 #14 0x00007fcc511e7183 in quota_copy (ctx=0x15d3b20, mail=0x15cf300) at quota-storage.c:220 #15 0x00007fcc520cc01f in mailbox_copy (_ctx=<value optimized out>, mail=0x15cf300) at mail-storage.c:2133 #16 0x000000000040c63b in fetch_and_copy (cmd=0x1593810, move=false) at cmd-copy.c:70 #17 cmd_copy_full (cmd=0x1593810, move=false) at cmd-copy.c:123 #18 0x0000000000416fbd in command_exec (cmd=0x1593810) at imap-commands.c:158 #19 0x00000000004160e0 in client_command_input (cmd=0x1593810) at imap-client.c:780 #20 0x00000000004161cd in client_command_input (cmd=0x1593810) at imap-client.c:841 #21 0x000000000041644d in client_handle_next_command (client=0x1592fb0) at imap-client.c:879 #22 client_handle_input (client=0x1592fb0) at imap-client.c:891 #23 0x00000000004167bf in client_input (client=0x1592fb0) at imap-client.c:933 #24 0x00007fcc51e1f336 in io_loop_call_io (io=0x158c1d0) at ioloop.c:388 #25 0x00007fcc51e203a7 in io_loop_handler_run (ioloop=<value optimized out>) at ioloop-epoll.c:220 #26 0x00007fcc51e1f2a8 in io_loop_run (ioloop=0x157b720) at ioloop.c:412 #27 0x00007fcc51dcdf73 in master_service_run (service=0x157b5b0, callback=<value optimized out>) at master-service.c:566 #28 0x000000000041fd07 in main (argc=1, argv=0x157b390) at main.c:400 Here's config: auth_debug = yes auth_master_user_separator = * auth_username_format default_vsz_limit = 512 M disable_plaintext_auth = no dotlock_use_excl = no first_valid_gid = 101 first_valid_uid = 102 imap_id_send import_environment = TZ info_log_path = /var/log/dovecot.log log_path = /var/log/dovecot.log log_timestamp = "%Y-%m-%d %H:%M:%S " mail_fsync = always mail_gid = 101 mail_location = maildir:%h/Maildir mail_max_userip_connections = 50 mail_nfs_index = yes mail_nfs_storage = yes mail_plugins = quota expire fts fts_lucene mail_log notify mail_uid = 102 maildir_broken_filename_sizes = yes managesieve_notify_capability = mailto managesieve_sieve_capability = fileinto reject envelope encoded-character vacation subaddress comparator-i;ascii-numeric relational regex imap4flags copy include variables body enotify environment mailbox date ihave 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 = INBOX. separator = . subscriptions = yes type = private } passdb { args = /opt/dovecot-2.2.10/etc/dovecot/passwd.masterusers driver = passwd-file master = yes } passdb { args = /opt/dovecot-2.2.10/etc/dovecot/dovecot-ldap.conf driver = ldap } passdb { args = /opt/dovecot-2.2.10/etc/dovecot/dovecot-ldap-multiuser.conf driver = ldap master = yes } plugin { fts = lucene fts_lucene mail_log_events = delete undelete expunge copy mailbox_delete mailbox_rename mail_log_fields = uid box msgid size quota = maildir quota_rule2 = INBOX.Trash:storage=+100M } protocols = imap pop3 service anvil { client_limit = 3000 } service auth { client_limit = 4096 unix_listener auth-userdb { mode = 0600 } } service imap-login { inet_listener imap { address = 10.11.47.49 port = 143 } inet_listener imaps { address = 10.11.47.49 port = 993 ssl = yes } process_limit = 2500 process_min_avail = 5 } service imap { drop_priv_before_exec = yes process_limit = 2500 process_min_avail = 5 } service managesieve-login { inet_listener sieve { port = 4190 } process_min_avail = 0 service_count = 1 vsz_limit = 64 M } service managesieve { drop_priv_before_exec = yes process_limit = 1024 } service pop3-login { inet_listener pop3 { address = 10.11.47.49 port = 110 } inet_listener pop3s { address = 10.11.47.49 port = 995 ssl = yes } process_limit = 300 process_min_avail = 5 } service pop3 { drop_priv_before_exec = yes process_limit = 300 process_min_avail = 5 } ssl_cert = </opt/dovecot-2.2.10/certs/imapd.pem ssl_key = </opt/dovecot-2.2.10/certs/imapd.pem userdb { args = /opt/dovecot-2.2.10/etc/dovecot/dovecot-ldap.conf driver = ldap } protocol lmtp { mail_plugins = quota expire fts fts_lucene mail_log notify sieve } protocol lda { mail_plugins = quota expire fts fts_lucene mail_log notify sieve } protocol imap { mail_plugins = quota imap_quota mail_log notify } protocol pop3 { mail_plugins = quota mail_log notify pop3_uidl_format = UID%u-%v } Regards, Ramon