but in the page on migration https://wiki2.dovecot.org/Migration/Dsync it seems to use a sixth undocumented "imapc:" option for destination
e.g. doveadm -o mail_fsync=never backup -R -u user@domain imapc: "imapc:" is also referenced on https://wiki2.dovecot.org/Migration/GmailIs https://wiki2.dovecot.org/Tools/Doveadm/Sync#section_arguments missing this option?
Andrew