Deliverdb in a memcached

[Ram]

On a very busy Imap server , duplicate suppression sometimes becomes the 
bottleneck
I have seen that If I disable duplicate suppression , my lmtp deliveries 
are speeded up.

Duplicate suppression is important , but the database need not persist 
for very long.
I have seen in most of the cases if there is a duplicate mail ( due to 
forwards , groups etc ), it arrives within 10 minutes of the first mail
( Any exception to this is too minor and can be ignored )


IMHO There should be a configuration that the deliverdb can be, 
optionally,  stored in memcached or directly in memory.
Of course there are cons .. like loss of data on restart etc. But these 
are OK.

Thanks
Ram