don't understand error message

Mon Sep 22 05:59:35 UTC 2014

new installation of Dovecot 2.0.9 on Centos
# telnet localhost 143
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE
STARTTLS AUTH=PLAIN] Dovecot ready.
LOGIN JohnDoe JohnDoe
LOGIN BAD First parameter in line is IMAP's command tag, not the command
name. Add that before the command, like: a login user pass
^]
telnet> quit
Connection closed.

What's generating this error?  Using samba4 ad for passdb/userdb.
Robert