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Moving to the Cloud environment is no more sci-fi, it is reality. When more and more companies are transferring to Office 365, more administrators are asking the question “Are we safe there? Do we still need to do a backup of our critical data?” Others do not even bother asking, trusting that globally dispersed MS datacenters are ensuring full safety of company’s data.

In the following blog post, I’ll try to answer these questions and check the native data backup and preservation options available in MS Office 365 plans.

Let’s get it straight right from the start – there is no backup option available in Office 365. At least not in the form administrators could remember from the on-premises environments. Microsoft concluded that since all information is stored in their datacenters, which provide super-safe environment, there is no need for such a functionality. Period.

On the other hand, MS is not a charity organization and storage room on their servers comes with a price, which changes across different Office 365 plans. Additionally, each plan has its own limits of storage, data preservation time-span, etc.

So how exactly Office/Exchange 365 stores my data? What happens when storage is up?

All mailboxes across all plans have storage limit of 25 GB, which seems to be quite enough. However, a message itself, even very small, can carry something that really pumps up the size of the inbox –  it is email’s attachment. Therefore, 25 GB might be an ocean of storage for text, but not necessarily for those numerous PDF, zip and BMP attachments.

So when the amount of data stored in the mailbox reaches the 24.5 GB threshold, the mailbox user receives a warning message about that. This should blink an amber light to start cleaning things up.

Next, when the user does not try slimming the mailbox down, and brings it to the 24.75 GB level, he or she receives a notification that no email sending is possible, until some stuff is deleted.

Lastly, when the final frontier (25 GB) is reached, the notification reads: “No sending, no receiving emails possible – clean up your mailbox finally!” (or something similar along these words).

Additionally the 365 server itself helps keeping the mailbox small by automatically cleaning the Deleted items folder (which is in the same 25 GB limit as the whole mailbox) with the Retention policy.

It is an automatic service that removes items from the mailbox after a specified amount of time. In other words, the retention service checks the “age” of each item in the mailbox, and depending on the specified limit removes it from the mailbox storage. It can be configured to proceed with the retention in steps, e.g. item placed in the Deleted items folder stays there for 30 days, after that period the retention service moves the item to another folder, Recoverable items (Dumpster), where it stays for another 14 days. After that the item is permanently removed.

I don’t want to delete anything – I want to archive!

Archiving items from the mailbox is a good method of trimming your data down and freeing some space up. Luckily, this feature is also available in Office 365. Check the table below to see how it works across different plans.

Terms used in the table:

• Storage quota – the available storage room on the server assigned to a specific organizational unit.
  E.g. quota of 25 GB per mailbox means that this is available room for all items and folders within one mailbox. Quota of 25 GB per archive means the storage room for all items included in the archive folder of the mailbox.
• Archiving – with this feature enabled for the 365 mailbox, the default retention policy moves messages older than 2 years to the special archive mailbox for preservation.
• Retention policy –an automatic service that removes items from the mailbox after a specified amount of time. It applies to different folders, including archive mailbox, dumpster etc.
• Litigation hold – also called legal hold. If your company is involved in any legal actions, and they require preserving unaltered data from the specific mailbox, you can put that mailbox on litigation hold. When enabled this feature stores all items indefinitely including deleted items and dumpster. Additionally dumpster also keeps all changed items from the primary mailbox (versioning of items).

It is not a surprise that only the two most expensive plans give you the largest storage space and the longest retention periods.

For example – the mailbox on 365 E1 plan has a storage limit of 25 GB. One would think “Ok – let’s enable archiving to save room”, but it won’t work. In E1 you are just pushing messages from one pile to another without freeing space in your mailbox, as your precious 25 gigs are shared between primary mailbox and archive.

Only E3 and E4 plans give you a real archive. It is separate from your primary mailbox storage quota, and it has virtually unlimited capacity. Well, not “unlimited” but “just” 100 GB, which should suit most users well. Plus it can be extended by MS team with no hassle. Simply pay more for higher tiered plan, which is 10 000 USD per month for 500 users in E3 (compared to 4000 USD per month for 500 users in E1 plan).

What else can I do?

The other idea to preserve data would be to extend all our retention policies! No luck here either. The retention policies applied to the recoverable folder (dumpster) can be max 30 days long, plus the dumpster also has its own stiff storage quota (30 GB).

“Ok, no big archive, no 20 years long retention policy – maybe a litigation hold?” This would be quite a solution – when a mailbox is on the litigation hold it keeps all data in a dumpster permanently (no retention time limit) and without a storage limit (no quota). However, this option has been created solely for the legal actions in your company, and it requires a designated person responsible for putting a mailbox on such hold (discovery manager, lawyer, or other authorized official). And it is available only in plans E3 and E4.

You can always create additional mailboxes in lower plans, to store data, but that comes with an additional license monthly fee. The same happens with mailboxes for employees that are no longer in your company – you still need to pay for their mailbox license. If you decide to reassign that license to another person, then you have 30 days to save old mailbox somewhere. After that time – it is removed forever with all the important emails in it.

There is a last resort, which is saving an Office 365 mailbox to local PST file. Good ol’ Outlook comes in handy again! But (there are always “buts”…) you can do only one mailbox at a time and you can’t use OWA. There are no fancy Power Shell commandlets for that purpose, so if you need to save 50 mailboxes, get ready to do some overtime.

Need to back up your data to your own on premises server ?

Microsoft says that with 365 and with the dawn of the cloud computing, regular backups on these dusty DLT tapes are things of the past, but if you ask me – I sleep much better when I know, that my business data is safe, with not all eggs in one basket.

For those companies who for security, legal or other reasons need to back up their 365 data to their own servers we are preparing a smart archiving tool. Click here if you’d like to find out more.