[Dovecot] Possible fix to an old Thunderbird related problem

[Marc Perkel]

I think I might have finally fixed it. The problem was that the 
max_cached_connections in Thunderbird defaults to 25 and I had login 
process count set to 10. I think raising it to 25 ill fix it. Just 
posting this in case others are having this problem.

What was happening was that the message counts were increasing but the 
messages didn't show up in the list. Or messages would appear to be 
empty. Restarting Dovecot or restarting Thunderbird fixes the problem 
temporarily. I'm hoping this annoyance will go away now.