On 12 Mar 2019, at 10.21, Kostya Vasilyev via dovecot <dovecot@dovecot.org> wrote:

It makes no difference if the IDLE connection does SELECT or SELECT (CONDSTORE) prior to going IDLE.

But then as far as I know (?) - in Dovecot, once any connection uses CONDSTORE ever, even once, Dovecot creates data structures to track MODSEQ values, and those data structures are forever.

So are you saying that you can reproduce if you do for a completely new user:

doveadm exec imap -u testuser1

a select inbox

b idle

And then run:

echo foo | doveadm save -u testuser1

doveadm flags add -u testuser1 '\Seen' mailbox inbox 1

And the EXISTS shows up immediately after saving, but the flag change won't show up? It works fine with me.

Do you see any errors in "doveadm log errors"? Can you reproduce this if you try with some other mailbox format than mbox?