imapc_host = imap.company.com
imapc_user = %u@company.com
imapc_password =  mypassword
imapc_features = rfc822.size fetch-headers
imapc_port = 143
pop3c_host = pop3host.company.com
pop3c_user = %u@company.com
pop3c_password = mypassword
pop3c_port = 110
namespace pop3c {
   prefix = POP3-MIGRATION-NS/
   location = pop3c:~/pop3c
   list = no
   hidden = yes
}

!include /etc/dovecot/dovecot.conf

plugin {
  pop3_migration_mailbox = POP3-MIGRATION-NS/INBOX
  pop3_migration_skip_size_check = yes
  pop3_migration_ignore_missing_uidls=yes
}
mail_prefetch_count = 20
mail_shared_explicit_inbox = no
protocol doveadm {
  mail_plugins = $mail_plugins pop3_migration
}

sudo doveadm reload

# doveadm -Dv
  -o imapc_host=<SOURCE_HOST>
  -o imapc_user=<SOURCE_USERNAME>
  -o imapc_password=<SOURCE_PASSWORD>
  -o imapc_features=rfc822.size
  -o imapc_ssl=starttls
  -o mail_fsync=never
   backup -R -u <DESTINATION_MAILBOX> imapc:

# doveadm -Dv
  -o imapc_host=<SOURCE_HOST>
  -o imapc_user=<SOURCE_USERNAME>
  -o imapc_password=<SOURCE_PASSWORD>
  -o imapc_features=rfc822.size
  -o imapc_ssl=starttls
  -o mail_fsync=never
  sync -1 -R -u <DESTINATION_MAILBOX> imapc: