Strange log message in /opt/zimbra/log/mailog.log

[paso70]

Hi guys,
I'have a zimbra test server (mytestserver.com) with some user (emailuser001@mytestserver.com, emailuser002@mytestserver.com, ecc...).
Today I've found this message in /opt/zimbra/log/mailog.log:

2017-06-27 08:43:31,784 INFO [ImapSSLServer-4235] [name=emailuser001@mytestdomain.com;mid=23;ip=192.168.1.46;ua=Thunderbird/38.6.0;] imap - dropping connection for user emailuser002@mytestdomain.com (server-initiated)

What does it means??
It means that user: emailuser001@mytestdomain.com try to connect from ip: 192.168.1.46 with Thunderbird email client, to mailbox user: emailuser002@mytestdomain.com ??
Or what else??
Thanks a lot!
R