Mailbox browser doesn't trigger mail check

I would like to press 'y' (<browse-mailboxes>), leave the mutt session idle, and
still be notified of new mail. Is this possible?

I use isync. Sync'ing my mail ahead of time and subsequently running
'mutt -y' works as expected, but I get no further notifications.

Entering a mailbox (any mailbox) does get me notified, but not until I
leave the mailbox browser.

There was a relevant discussion 9 years ago

https://mutt-users.mutt.narkive.com/FsclJ1Rh/new-mail-indicator-in-browser-view

but the solution (if this *is* one) would take me way outside mutt.


Many thanks.