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I would like to get a recommendation regarding mailbox hosting with quota.
What kind of overbooking do you accept for Business usage?

For instance, if I have x mailbox of 100megs and 10 Gig of space, how many mailbox can I setup? 200 (so 200% overbooking), 400...?

Thanks and regards,

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Why would you want to over book? Shouldn't your booking be some percentage less than your actual allotted storage? Personally I would maintain the booking at somewhere around 75 to 80% of my total capacity.

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Because if you count like this, it might cost a lot in term of HDD, here we use SAS drive, 15K 2.5", those drive aren't cheap. – Henry-Nicolas Tourneur Sep 9 '10 at 14:50
Right, but you're selling capacity to your customers that you may not be able to deliver because of over booking. How well will that work out for you? – joeqwerty Sep 9 '10 at 14:53
Ok so I'll stick with the 100% percent logic. – Henry-Nicolas Tourneur Sep 10 '10 at 9:55

There is no reasonable way to answer this because this depends only on your users and the type of emails they receive. As an example, if you have many graphic artists, they will receive lots of big emails, while an account may only receive a few small excel files.

Start with a low value and look how your users use this. If possible, you can still increase the quota afterwards.

But generally I would just throw more storage at the mail system if I run out of it, as long as I don't have to support thousands of users.

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Ok so it's based on the experience. My problem is that I got a situation as-is, if a new customer comes and tell me : I want 60 mailboxes of 2 Gig each, it'll cost a lot in term of HDD, for a normal company, what kind of overbooking would you use as a starting point? – Henry-Nicolas Tourneur Sep 9 '10 at 14:52
As joeqwerty pointed out you have to be able to deliver on what you sold. So, my answer would be 100%, reserve 120GB for them, maybe 100GB if you can act fast and add storage if necessary. But why do you need these expensive 15k SAS drives for an e-mail system? – Sven Sep 9 '10 at 15:32
Because that's what I can put in my server :) – Henry-Nicolas Tourneur Sep 10 '10 at 9:41
Then you need o get the approrpriate server hardware. – TomTom Oct 28 '10 at 22:31

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