[Dovecot] No authentication sockets found

[Stewart Dean]

Thunderbird (2.0) is all of a sudden checking mail server capabilities 
and keep posting a popup saying:
"Mail Server imap.bard.edu is not an IMAP4 mail server".  To the best of 
my knowledge, neither Tbird nor DC have been updated, though the DC imap 
host was rebooted today 3 hours ago.  Any info on what this is about?  
DC is currently serving out of a special port and in evaluation 
list....I can't imagine that this message would please the user 
community!   Killing and restarting dovecot appears to have at least 
temporarily stopped this behavior.

Also and perhaps related, I am seeing a syslog message:
imap-login: No authentication sockets found
child xxxxxx (login) returned error 89

using SSL encrypted IMAP service

Background: DC 1.0, invoked from /etc/rc.local during boot.  After 
stopping and restarting DC, things seem to work again. As per an old 
problem, I checked /var/run/dovecot, but it was empty with plenty of 
space.  FWIW, the owner/group for login dir (/var/run/dovecot) is 
dovecot:dovecot, perm 755, while /var/run/dovecot/login is root:dovecot, 
750.
Host is running AIXV5.3 TL5 SP6 (latest level), DC is compiled with 
IBM's AIX for C, V6.0
dovecot -n output
> # /usr/local/etc/dovecot.conf
> listen: *:10143
> ssl_listen: *:10943
> disable_plaintext_auth: no
> verbose_ssl: yes
> login_dir: /var/run/dovecot/login
> login_executable: /usr/local/libexec/dovecot/imap-login
> verbose_proctitle: yes
> first_valid_uid: 200
> mail_location: mbox:~/mail:INBOX=/var/spool/mail/%u:INDEX=/var/dcndx/%u
> mail_debug: yes
> mbox_dirty_syncs: no
> mbox_lazy_writes: no
> auth default:
>   verbose: yes
>   debug: yes
>   passdb:
>     driver: pam
>   userdb:
>     driver: passwd
Do I need to set an O/S or SSL max for authentication sockets?  If so, 
any info would be appreciated

Thanks!

-- 
====
Stewart Dean, Unix System Admin, Henderson Computer Resources 
Center of Bard College, Annandale-on-Hudson, New York  12504  
sdean at bard.edu  voice: 845-758-7475, fax: 845-758-7035