Please re-read the upgrade documentation:
https://www.cyrusimap.org/imap/download/upgrade.html
In particular, please consult section 5, which includes this warning:
To check your entire system’s configuration you can use the conf-all
action. This command takes all the system defaults,
Using imapsync we are attempting to move our mail store from an
Cyrus-IMAPd-2.3.16 running under CentOS-6.9 to a Cyrus-IMAPD-3.0.4
running under FreeBSD-11.1p6. In all instances we are using software
as packaged by the respective distribution.
On our existing system our user mailboxes are
The Cyrus team is proud to announce the immediate availability of a new
version of Cyrus IMAP: 3.0.4
This release contains important security fixes, as well as bug fixes.
Download URLs:
http://www.cyrusimap.org/releases/cyrus-imapd-3.0.4.tar.gz
http://www.cyrusimap.org/releases/cyrus
