Comment 134 for bug 704623

(In reply to Miroslav Suchý from comment #89)
> Thunderbird 38 is currently in Fedora stable so I gave it try.
> I tried to reset mail.db.max_open to default value. While the lags are not
> so big, after while I still found some. It was like 5 secons vs. 50 seconds
> as when I originally reported this issue.
> After few hours I set mail.db.max_open back to 1000 and even those 5 secs
> lags are gone.

Miroslav,
What happens if you set mail.db.max_open to something more modest, like 60?