dovecot - Aug 2022 - Should one prevent reconnection before expunge?

Hello. From my understanding the 'autoexpunge' feature activates on 
user disconnect.

But could you help me understand the 'doveadm expunge' feature better?

If a Maildir has 20 thousand messages and user is reading it over IMAP I 
have a suspicion it is not a good idea to be rewriting the dovecot cache 
at the same time.

Should I temporarily prevent login (e.g. with passwd-file deny) and then 
kick them before the expunge?

Thank you.

On Fri, 12 Aug 2022, Jack Cecil wrote:
> could you help me understand the 'doveadm expunge' feature better?
>
> If a Maildir has 20 thousand messages and user is reading it over IMAP 
> I have a suspicion it is not a good idea to be rewriting the dovecot 
> index and cache at the same time.
>
> Should I temporarily prevent login (e.g. with passwd-file deny) and 
> then kick them before the expunge?
Hi. Could someone please drop me a hint? I have 309 users that will be 
very angry with me if their Thunderbirds start displaying 0 messages :(

Thanks.