On 4 Dec 2017, at 19.59, Webert de Souza Lima webert.boss@gmail.com wrote:
On Mon, Dec 4, 2017 at 9:16 AM, Sami Ketola sami.ketola@dovecot.fi wrote:
With every other tool you will face end users needing to invalidate their local caches and redownloading all headers if not also all mail bodies.
Sami
I don't think so. Been using imapsync for large scale migrations from external servers to our dovecot setup. Users don't even see it when the key is switched (DNS changes). Go for it.
You are wrong. There is no way to assign IMAP UID:s over IMAP protocol. It simply does not support it. With imapsync there is absolutely no way to preserve them and you will face problems with IMAP UID:s not matching the cached mail anymore.
Trust us. We have run multiple migrations at scale of 10+ million users.
Sami