I am having an odd problem in dovecot, the first time I try to login via telnet dovecot gives a error, the second time it works, both within the same telnet session. This is the telnet session, note the 'BAD Error in IMAP command received by server' and the "a OK" just after that : telnet 192.168.1.2 143 * OK Waiting for authentication process to respond.. * OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE STARTTLS AUTH=PLAIN] Dovecot ready. a login someUserLogin supersecretpassword * BAD Error in IMAP command received by server. a login someUserLogin supersecretpassword a OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS MULTIAPPEND UNSELECT CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS] Logged in dovecot configuration >dovecot -n # 2.0.19: /etc/dovecot/dovecot.conf # OS: Linux 3.5.0-34-generic x86_64 Ubuntu 12.04.2 LTS auth_debug = yes auth_verbose = yes disable_plaintext_auth = no login_trusted_networks = 192.168.1.0/16 mail_location = maildir:~/Maildir passdb { driver = pam } protocols = " imap" ssl_cert = </etc/ssl/certs/dovecot.pem ssl_key = </etc/ssl/private/dovecot.pem userdb { driver = passwd } This is the log file: Jul 3 12:27:51 linuxServer dovecot: auth: Debug: Loading modules from directory: /usr/lib/dovecot/modules/auth Jul 3 12:27:51 linuxServer dovecot: auth: Debug: auth client connected (pid=23499) Jul 3 12:28:06 linuxServer dovecot: auth: Debug: client in: AUTH#0111#011PLAIN#011service=imap#011secured#011no-penalty#011lip=192.168.1.2#011rip=192.169.1.3#011lport=143#011rport=50438#011resp=<hidden> Jul 3 12:28:06 linuxServer dovecot: auth-worker: Debug: Loading modules from directory: /usr/lib/dovecot/modules/auth Jul 3 12:28:06 linuxServer dovecot: auth-worker: Debug: pam(someUserLogin,192.169.1.3): lookup service=dovecot Jul 3 12:28:06 linuxServer dovecot: auth-worker: Debug: pam(someUserLogin,192.169.1.3): #1/1 style=1 msg=Password: Jul 3 12:28:06 linuxServer dovecot: auth: Debug: client out: OK#0111#011user=someUserLogin Jul 3 12:28:06 linuxServer dovecot: auth: Debug: master in: REQUEST#0111823473665#01123499#0111#0113a58da53e091957d3cd306ac4114f0b9 Jul 3 12:28:06 linuxServer dovecot: auth: Debug: passwd(someUserLogin,192.169.1.3): lookup Jul 3 12:28:06 linuxServer dovecot: auth: Debug: master out: USER#0111823473665#011someUserLogin#011system_groups_user=someUserLogin#011uid=1000#011gid=1000#011home=/home/someUserLogin Jul 3 12:28:06 linuxServer dovecot: imap-login: Login: user=<someUserLogin>, method=PLAIN, rip=192.169.1.3, lip=192.168.1.2, mpid=23503, secured