Now that I have some stats coming in from the message cache - it is not very useful when you have a large mailbox.
If your mailbox exceeds the cache size the best hit rate you get when the server is not very busy is 50% on some mailboxes.
Most of the time (>90%) the hit rate is single digits or zero.
For the little complexity it adds and the memory use it takes up it is better to just not have a message cache. Since the cache hit rate is so poor and a lot of response time is simply taken up by asyncio I do expect almost no loss in performance.
Now that I have some stats coming in from the message cache - it is not very useful when you have a large mailbox. If your mailbox exceeds the cache size the best hit rate you get when the server is not very busy is 50% on some mailboxes. Most of the time (>90%) the hit rate is single digits or zero.
For the little complexity it adds and the memory use it takes up it is better to just not have a message cache. Since the cache hit rate is so poor and a lot of response time is simply taken up by asyncio I do expect almost no loss in performance.