This morning I have a Outlook 2007 user who getting the error and I am unsure how to fix it.

Cannot open this item. The server responded: "Error in IMAP command UID FETCH: Invalid uidset'

DoveCot v 1.2.9

# 1.2.9: /etc/dovecot/dovecot.conf # OS: Linux 2.6.32-27-generic-pae i686 Ubuntu 10.04.1 LTS log_timestamp: %Y-%m-%d %H:%M:%S protocols: imap imaps pop3 pop3s managesieve listen(default): * listen(imap): * listen(pop3): * listen(managesieve): *:2000 disable_plaintext_auth: no login_dir: /var/run/dovecot/login login_executable(default): /usr/lib/dovecot/imap-login login_executable(imap): /usr/lib/dovecot/imap-login login_executable(pop3): /usr/lib/dovecot/pop3-login login_executable(managesieve): /usr/lib/dovecot/managesieve-login mail_privileged_group: mail mail_location: maildir:~/ mmap_disable: yes mail_nfs_storage: yes mail_nfs_index: yes mbox_write_locks: fcntl dotlock mail_executable(default): /usr/lib/dovecot/imap mail_executable(imap): /usr/lib/dovecot/imap mail_executable(pop3): /usr/lib/dovecot/pop3 mail_executable(managesieve): /usr/lib/dovecot/managesieve mail_plugins(default): quota imap_quota mail_plugins(imap): quota imap_quota mail_plugins(pop3): quota mail_plugins(managesieve): mail_plugin_dir(default): /usr/lib/dovecot/modules/imap mail_plugin_dir(imap): /usr/lib/dovecot/modules/imap mail_plugin_dir(pop3): /usr/lib/dovecot/modules/pop3 mail_plugin_dir(managesieve): /usr/lib/dovecot/modules/managesieve imap_client_workarounds(default): tb-extra-mailbox-sep imap_client_workarounds(imap): tb-extra-mailbox-sep imap_client_workarounds(pop3): imap_client_workarounds(managesieve): pop3_client_workarounds(default): pop3_client_workarounds(imap): pop3_client_workarounds(pop3): outlook-no-nuls oe-ns-eoh pop3_client_workarounds(managesieve): managesieve_logout_format(default): bytes=%i/%o managesieve_logout_format(imap): bytes=%i/%o managesieve_logout_format(pop3): bytes=%i/%o managesieve_logout_format(managesieve): bytes ( in=%i : out=%o ) namespace: type: private separator: / inbox: yes list: yes subscriptions: yes lda: postmaster_address: hostname: auth_socket_path: /var/run/dovecot/auth-master mail_plugins: quota sieve log_path: info_log_path: syslog_facility: mail auth default: username_format: %Lu passdb: driver: ldap args: /etc/dovecot/dovecot-ldap.conf passdb: driver: sql args: /etc/dovecot/dovecot-sql.conf passdb: driver: ldap args: /etc/dovecot/dovecot-ldap.conf passdb: driver: ldap args: /etc/dovecot/dovecot-ldap.conf userdb: driver: ldap args: /etc/dovecot/dovecot-ldap.conf userdb: driver: sql args: /etc/dovecot/dovecot-sql.conf userdb: driver: ldap args: /etc/dovecot/dovecot-ldap.conf userdb: driver: ldap args: /etc/dovecot/dovecot-ldap.conf socket: type: listen master: path: /var/run/dovecot/auth-master mode: 432 user: vmail group: vmail plugin: quota: maildir quota_rule: *:bytes=20M sieve: ~/sieve/.dovecot.sieve sieve_dir: ~/sieve sieve_global_path: /var/mail/default.sieve sieve_before: /var/mail/sieve/global sieve_extensions: +imapflags