Timo Sirainen wrote:
On Wed, 2009-08-12 at 15:42 -0400, Charles Marcus wrote:
- and I've never heard of any other mail server supporting such a thing.
Exchange does... and is the single and only reason I have *considered* switching to it <shudder> in the past few years...
I heard that the next Exchange version drops that feature, because it typically causes more disk I/O when reading. I don't know if it's still possible to enable it optionally though.
It also had a bunch of limitations, it was basically only single instance for CC recipients on a message (more or less). Quite a lot of things such as certain types of virus scanning would (I think) easily disable the single instance storage also?
So I doubt it would help in most of the cases mentioned here, ie each time it was re-forwarded internally it would not be single instanced
I still think it would be instructive to do some benchmarks though - often these things look good on paper, but are surprisingly less effective (given the implementation cost) when measured. I'm not disagreeing, just would be interested to see some numbers...
I think perl's Mimetools would make it pretty easy to build something which scanned all files and created a hash of all interesting attachments. Quite possibly there is an even more clever way to get the same through misusing some Dovecot feature?
Good luck!
Ed W