UI sluggish when imap_check_subscribed is set

[Naveen Nathan]

Hi,

I'm running Mutt 1.13.4 on MacOS using homebrew.

When I set imap_check_subscribed and browse the index
such as scrolling downwards, every few seconds the UI
seizes.

Is this due to a short period of polling to check if
subscribed folders have new messages? I think I have
on the order of 30+ folders subscribed.

Thanks,
Naveen