All business professionals run into mailbox space issues at some point.  There are mailbox limitations whether you have you server hosted locally or in the cloud.  We break down several ways to free up space in your mailbox, archive your older email, and backing it up.  Archiving is essential to optimizing your mailbox, protecting your organization from the threat of legal action, and compliance.  EMail backup in Outlook comes in many different forms and understanding all the lingo that comes with it can make or break your potential day of disaster.  We have additional posts on optimization and setup too if below is not what you are looking for.

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Organizations without Exchange

In the past, it was best to copy the PST to your file server.  This evolved if you migrated to Microsoft Exchange or Office 365 but for now let’s talk about that database file called PST.  The copy of your PST is typically stored in the  H:\ drive.

Backup That PST eMail backup in Outlook

Alternatively, the user should have backup software for the Outlook files location of your documents if you don’t have a file server.  Otherwise, you will lose your archived email data when the local workstation fails.  Does that make sense?  Please have a copy of your 2016 PST database file and older in your documents (outlook files) and a redundant copy on your file server in case the desktop or laptop fails.  Here’s a nice little illustration of Mozy backup software to break it down for you.

eMail backup in Outlook


Auto Archive

For the exchange users, we are all for Online Archiving.  Archiving to PST is a minefield of lost data & corrupt files.  But for the IMAP mailboxes I can’t really think of a good option outside of AutoArchive in outlookOnline Archiving’s only caveat is backup/data protection.  We are not opposed to auto archiving. We just feel data protection and central management makes it more appealing.  We only do manual archiving for our IMAP clients, I move all the data out by year (typically) into managed PST files that are backed up. Well worth the time for those with years of data.


Slicing and Dicing Your PST

eMail backup in Outlook






This is not recommended if you have the right processes in place.  Copy the data in small chunks or Outlook will crash; and you will have to start the process again.  Here’s snap of what 2 months of email data looks like during its transfer phase.  You may have repeat months over and over again to grab all data if you using Exchange.  IMAP behaves a little differently and the data may be transferred but it may repopulate under their inbox.  Whatever the case, confirm the data has been moved and delete from the inbox if absolutely necessary.

eMail backup in Outlook




Organizations on Exchange

The best option for the Exchange accounts is just to set outlook to only cache the last year or two years’ worth of email, this way the outlook performance is improved without having to do manual archive, the  user can then also search for these emails if required and they are stored centrally in Exchange.


Organizations on Exchange – Office 365

Hire a managed IT company for setup, maintain, and implement infrastructure or setup a Synology and do it yourself.


Office 365 Exchange Archiving

Does the archive that I enabled in office 365 go away if I delete the user’s mailbox?

  • Archived emails will be retained for maximum of 30 days including ALL emails and the User Account itself. Also, user can be restored within 30 days including the Archived emails.

Local Hosted Exchange

Exchange has retention policies that you can control the age to move the emailsand still have the users have access to them If they are in exchange 2007 or newer.  Messaging records management (MRM) is the records management technology in Microsoft Exchange Server 2010 that helps organizations reduce legal risks associated with e-mail and other communications. MRM makes it easier to keep messages needed to comply with company policy, government regulations, or legal needs, and to remove content that has no legal or business value.

Organizations formulate MRM policies that specify the retention period for different classes of e-mail messages. However, in the past, enforcing those policies has often been challenging. Attempts to automate the MRM process have met with limited success. The MRM functionality in Exchange 2010 addresses these challenges.  Refer to Technet for more details on the retention policies topic.

Looking for management tasks related to MRM? See Deploying Messaging Records Management.


Compact the Size of Your Mailbox

PSTs database files remain ridiculously big even if you move or deleted files.  Run the “Compact Now” feature in Outlook to decrease the size of your PST.




Rebuilding your index is a quick way to get your Outlook to behave properly when the search functionality has decided to freak out.


Optimization and eMail backup in Outlook Summary

Email backup in outlook along with all the associated optimization techniques can be a bit overwhelming.  Hopefully, this IT guide provides a bit more clarity.

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