imap not working postfix+dovecot

[Keith Smith]

Hi,

I can receive on 110/STARTTLS/Normal password

when I set to 143/STARTTLS/Normal password

I get a Thunderbird failure message:

An error occurred with the POP3 mail server. Mail server host.domain.tld 
responded:

/var/log/mail.log

Oct 12 17:54:00 Host-name dovecot: imap-login: Disconnected (no auth 
attempts in 4 secs): user=<>, rip=xxx.xxx.xxx.xxx lip=xxx.xxx.xxx.xxx, 
session=<44Tb96tDAqBQB>

/var/log/syslog contains the same message as above.

/var/log/mail.err shows no new entries

No new lines in /var/log/upstart/dovecot.log

nmap scan localhost says 143/tcp open  imap

dovecot-imap is installed.

When I go back to 110 the email I sent are pulled in when I check for 
mail.  It appears the emails are making it into my maildir, however I 
cannot retrieve with imap.

Not sure why I cannot configure imap.

Any help much appreciated.

-- 
Keith Smith