On 12/31/2018, 5:22:48 AM, Ignacio GarcĂa <y...@ignasi.com> wrote: > A totally different approach (that is imap-server agnostic), providing > that you're setting up those new accounts with temporary passwords > (which you know), before users change their passwords to their liking: > you could also use imapsync ( https://github.com/imapsync/imapsync) . We > here use it with a batch file and a text file containing all accounts to > do mass-migrations, usually at night, when there's little to none user > interaction with their mail accounts. I like this approach because mail > service never gets interrupted and we do programmed syncs all night in > case DNS propagation takes more than expected and mail still arrives to > the old server.
Or, you can use Master Passwords on both sides, and just do the migration at your leisure. I did this when migrating from our dovecot server to Office 365. Next time I'll look at using a dovecot method (DSync? doveadm?) but still using Master Passwords.