Managing mailbox storage use in Exchange 2010, Part 2

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In the previous part (yes, I know. It’s from May… I’m very ashamed) I discussed using PSTs or the built-in Personal Archive (also referred to as Online Archive).

In this post we will discuss third party archiving solutions and Exchange Online Archiving which in this case is service part of Office 365, although you can mix it with an on premises solution. (see the possible confusion)

Third Party Archiving

Archive CabinetAs it seems, organizations had long ago issues with overflowing Exchange stores and storage. In that niche, numerous third parties like Metalogix Archive Manager, Symantec Enterprise Vault or GFI MailArchiver, filled the need. However, there are two ways at looking at archiving; storage or compliancy focused (or in between).

Third Party archiving advertise with storage management. That is indeed something they can help in and was at first their main focus, understandable as storage was expensive but email was not regarded the same importance as it is now. In my view their current best strong suit on archiving has now changed to compliancy regulations. Especially since SOX etc.. these solutions are sometimes indispensible.

Some customers automatically propose a third party archiving solution, because they have a lot of data etc. etc.. But I am skeptical the moment this happens. Exchange 2010 isn't 2003 anymore and reasons to implements such a solution in the past could be no longer valid. To summarize, Archiving solutions may have started with storage maintenance but due to changing external factors and architectural changes in Exchange it’s focus has shifted towards compliancy. An important thing to realize, as it could affect your choice of storage management.

Most solutions require one dedicated server for the server application and storage of archived items. For metadata most times a SQL server is required. This could mean that instead of data reduction one is just shifting data from one place to another. That could be enough due to storage tiering etc.., but the extra overhead can not be discounted. Yes, if you have a DAG with multiple copies, this would reduce that amount. But you loose the same amount of redundancy with it, unless you take action for the archive and thus still have to account for at least twice the amount of storage the archive. Even if you only need compliancy, you will have to address these issues (some compliancy regulations specify a need to keep all mails for at least several years).

Furthermore, you have to take extra care backing up the archiving servers keeping it in sync. Nowadays this seems to be handled a lot better, but these solution always add an extra complexity to you environment. You have to decide whether this is worth it.

And last: these solutions are not for free and there are always additional licensing costs, most of the time per mailbox and or per specific feature. Also, don’t forget the Windows Server licenses and in some cases Microsoft SQL server licenses.


  • Flexible rules regarding archiving and compliancy (time, size based, only attachments etc. etc.)
  • Most of the times also compliancy built-in
  • Data stored outside the Exchange environment, sometimes with Single Instance Storage limiting even more storage space


  • Still need storage for archived mail, although less when there is no need for redundancy
  • Most of the time additional servers needed (for instance: File Storage, meta database, the service itself) and thus higher complexity
  • Additional administrative effort for maintaining archiving solution
  • Additional licensing fees (most solutions work per mailbox)

Third party archiving solutions can be helpful and are more flexible with archiving rules than Exchange own rules which are only based on the age of the item, but consider the investment you have to make especially if you don’t need it for compliancy reasons.

Exchange Online Archiving

The Exchange Online Archiving is basically the same as the Exchange Local Online Archive functionality mentioned in part 1 of this series. The difference here is that the Archive Mailbox is now located in Exchange Online. For this to work you do have to setup DirSync and Federation Services, just as an Hybrid Exchange environment. In fact, it is an hybrid environment but you don’t have to put main mailboxes in Exchange Online.

The upside is that you pretty much don't have to worry about archive storage because you don't host it. Availability, capacity etc. are all cared for by Office 365/Microsoft. Users don't even have to notice that their archive is not on-premises. You do have to pay a fee per mailbox, but the costs are predictable and it could very well be cheaper per GB than having it on you own storage solution.

You do need to account for extra administrative effort due to the Federation and DirSync services, although probably less than an Exchange server. If they are down, nobody can access their Archive Mailbox as they normally would, so monitoring and maintenance is required (although perhaps at a lower degree if Archive mailboxes are deemed less important). Another downside could be when the internet connection fails. Users can access their on-premises mailbox but not their Online Archive Mailbox.

Depending were your company is based or what kind of industry your company is operating, it could very well be that certain privacy or security guidelines or even laws limit or prevent you from using this solution. Especially in Europe (semi) governments aren’t always allowed to store information off-premise or on servers that could potentially be outside the country (not even if it’s an fellow EU country).  But even if you don’t have these legal prohibitions, there are still a lot of companies that don’t like to store their data (al be it older mails) off-premises with another company. Keep that in mind.


  • No local storage of archived data
  • Can be cheaper per GB than on-premises storage
  • No maintenance of archived data


  • Need for additional (Federation Services and DirSync) servers
  • Need for internet connection when access to Archive Mailbox is needed
  • Additional administrative effort on maintaining the Hybrid configurations
  • Additional fees per mailbox per month (however they are predictable)
  • Data is stored off premises which could have legal ramifications
  • The no control over your data could be a psychological barrier for some

Exchange Online Archive can be an easy solution depending on your situation, however most of the times legal and psychological barriers prevent you using this option.

This concludes part 2 of this series. The next and final part will discuss retention policies, mailbox quota’s and little bit about Outlook 2013.

Managing mailbox storage use in Exchange 2010, Part 1
Managing mailbox storage use in Exchange 2010, Part 3

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