hello.

Code:
zimbra@vvx-mail-01:~/log> zmcontrol -v
Release 8.0.1_GA_5438.SLES11_64_20121105164455 SLES11_64 NETWORK edition.
we are using thunderbird as imap-client and see that thunderbird can not connect sometimes.

in mailbox.log I see following error:
Code:
2013-01-17 15:59:25,485 ERROR [ImapServer-91] [name=user@domain.tld;ip=1.1.1.1;oip=2.2.2.2;via=1.1.1.1(nginx/1.2.0-zimbra);ua=Zimbra/8.0.1_GA_5438;] imap - IMAP ID with name/version is allowed only once per session, received different name/version: Thunderbird/17.0.2, command ignored

can anybody tell me more about this error?
what can I do to avoid this?

Code:
zmprov gs mailserver.com zimbraImapMaxConnections
# name mailserver.com
zimbraImapMaxConnections: 1500
Code:
zmprov gs mailserver.com zimbraImapNumThreads
# name mailserver.com
zimbraImapNumThreads: 900