Last month, I posted an article titled “What’s a good mailbox size?” where I discussed many of the considerations an architect must take into account when sizing storage for a new email system. In that post, I also set up a survey where I asked readers to answer six short questions about what they think makes a good size for a mailbox, as well as what future plans they might have for system growth. As promised in last month’s post, I am sharing the results of the survey now.

While the total number of respondents was somewhat less than I hoped for, the quality of those responses from survey participants is greatly appreciated. No one skipped any of the first four questions; the last two were “if” type and should have been skipped if not applicable. Thanks to all those who took the time to share their answers. I will share each question and the responses by percentage below.

1. What email system are you running now?

The vast majority of respondents are running Exchange, with a smattering of Notes, but nothing else apparently. While the dominance of Exchange was no surprise, that not a single Groupwise or Sendmail admin responded makes me wonder whether those products are dying out, or if their admins simply are too busy to deal with surveys.

2. What is the standard mailbox size (in MB) for regular users?

Almost half of those responding give standard users mailboxes less than half a gig. Those results shocked me on their own, but wait until you read question four!

3. What is the standard mailbox size (in MB) for special users (IT, executive, HR, or any other group that needs a larger mailbox)?

It looks like half of the admins who responded draw no distinction between regular users and special users. How egalitarian of you. We do see an uptick in the sizes though, with the other half of you giving special users 5 GB or more of storage space.

4. Is your current mailbox size adequate for the majority of users?

Okay, this is the answer that floored me. Over 90% of respondents feel their mailbox sizes are adequate. Considering how many provision regular users with less than half a Gigabyte, that is not at all what I would have expected. If you are one of those folks, please let us know in the comments how you do it. Do you have an aggressive deletion policy, an archiving solution, or do you just prohibit attachments? Inquiring minds want to know.

5. If you are considering a larger mailbox size for regular users, how big would you like that to be?

This is another response that did not come out like I expected. No one is looking for huge mailboxes (>25 Gigabytes) and most look like they would be happy with 10 GB or less. Storage vendors may weep to see this.

6. If you are considering a larger mailbox size for special users, how big would you like that to be?

Now we see an expected distinction, where special users will get much larger mailboxes. The designers of Exchange 2010 are smiling that so many of us share their vision.

So to summarise, the vast majority of regular users’ mailboxes are either in the 512MB range, or in the 1 to 5 GB range. In about half the cases, special users get a bump to 5 GB or larger. Most of us are happy with our mailbox sizes, but if we were going to increase them, it’s only the special users who’d really see a big change, and no one seems to want to go above 25 GB for mail.

Once again I’d like to thank those of you who participated in the survey for your time and the information you shared. I know it will be very useful to me, and I hope that other regular readers of TheEmailAdmin can also benefit from this.

Are there any other issues you’d like to see surveyed and discussed here? Any questions you’d love to see asked in such a large forum? If there are, leave a comment and if I get enough good ones, I will create another survey for the readers so we can see just how everyone else is doing it.