1) Migration to new host

a) On destination host
Install QMT/CentOS 7, instructions here.
toaststat (make sure all services are running)

b) On source [cdb] host
dhost=192.168.1.3 (change destination [mysql] host to suit)
ssh-keygen
ssh-copy-id $dhost
ssh $dhost (test, no password should be required)

# The first rsync migrates the bulk of the email database with vpasswd files except those queued during sync
rsync --progress -zv -are ssh /home/vpopmail/domains/ root@$dhost:/home/vpopmail/domains

# Stop qmail/dovecot on source host and destination hosts
qmailctl stop && systemctl stop dovecot

# The second rsync, services stopped, migrates the balance of the email database 
# and control files
rsync --progress -zv -are ssh /home/vpopmail/domains/ root@$dhost:/home/vpopmail/domains
rsync --progress -zv -are ssh /var/qmail/control/ root@$dhost:/var/qmail/control
rsync --progress -zv -are ssh /var/qmail/users/ root@$dhost:/var/qmail/users
rsync --progress -zv -are ssh /etc/tcprules.d/ root@$dhost:/etc/tcprules.d
rsync --progress -zv -are ssh /etc/dovecot/toaster.conf root@$dhost:/etc/dovecot
rsync --progress -zv -are ssh /etc/dovecot/local.conf root@$dhost:/etc/dovecot

# Not necessary to the migration
rsync --progress -zv -are ssh /usr/share/toaster/include/admin.pass  root@$dhost:/usr/share/toaster/include
rsync --progress -zv -are ssh /usr/share/toaster/include/admin.htpasswd  root@$dhost:/usr/share/toaster/include
rsync --progress -zv -are ssh /usr/share/squirrelmail/plugins/ root@$dhost:/usr/share/squirrelmail/plugins
rsync --progress -zv -are ssh /etc/spamassassin/.spamassassin/  root@$dhost:/etc/spamassassin/.spamassassin
rsync --progress -zv -are ssh /etc/spamassassin/local.cf  root@$dhost:/etc/spamassassin
rsync --progress -zv -are ssh /var/lib/squirrelmail/prefs/  root@$dhost:/var/lib/squirrelmail/prefs

c) On destination host
# Convert vpasswd files to mysql vpopmail db, aliases must be handled manually
/home/vpopmail/bin/vconvert -c -m
qmailctl cdb && qmailctl start && sleep 2s && systemctl start dovecot && toaststat





2) In place conversion*

# qmailctl stop && systemctl stop dovecot
# yum install -y yum-utils
# yum-config-manager --enable qmt-current
# yum reinstall qmail qmailadmin dovecot* ezmlm* vpopmail vqadmin
# /home/vpopmail/bin/vconvert -c -m
# qmailctl start && sleep 2s && systemctl start dovecot && toaststat
* Aliases must be done manually.
  Will convert to many domain format if 
  vpopamil was compiled with this option

Questions, comments, suggestions, corrections...contact Eric on the QMT list