neomutt: fix sidebar not showing unread highlight

dotfiles/neomutt/neomuttrc

@@ -35,6 +35,9 @@ set my_source_command = \
 # }}}
 # General {{{
 
+set mail_check_stats = yes
+set mail_check_stats_interval = 60
+
 set sort = 'reverse-date'
 set mark_old = no  # Unread mail stay unread until read
 set mailcap_path = ~/.config/neomutt/mailcap