See the links below to jump to the appropriate portion of this document for your next steps. 

• Basic Steps to Archiving / Moving Small Amounts of Email
  • Create the "receiving" folder
  • Search for messages by date
  • Move messages
• Advanced - if you need an immediate impact
  • Find the largest folders
  • Find the largest emails
• Moving LARGE amounts of email
  • Setup
  • Archiving email from primary mailbox
  • Importing email into archive mailbox
• Best Practices to avoid running out of space

What's the purpose of this document? 

The purpose is to help you move email from one email account to another to free up space in your primary mailbox.  NOTE: This is NOT the same thing as moving email from your "Inbox" folder to an "Archive" folder in your primary mailbox.  

While this may be done for any number of reasons, such as moving departmental email into a shared mailbox before retirement, this document focuses on archiving email between a primary mailbox and a secondary archive mailbox.  However, the process is the same regardless of the purpose of the 2nd mailbox.  

The first step is having access to both the "sending" mailbox and the "receiving" mailbox.  If you don't have access to an "archive" mailbox, email SCS Computing staff (scs-computing@illinois.edu) and we will talk with you about your situation and the best remedy.  

Why move email to an archive mailbox? 

University of Illinois inboxes are limited to 100 GB. There is no way to increase the size of a mailbox, either. But if you are approaching that limit, you'll need to take action because if you hit that limit, and you can't send or receive emails.  This limit is the cumulative total for ALL folders in your mailbox, not just your Inbox.  

If an email account is TRULY at or very near capacity, see the Advanced instructions below for being able to make an immediate impact by moving the largest emails first.  If you do that, please come back to the "Basic Steps" section to complete the migration of all mail in the desired time frame.  

Archiving options

Outlook for Windows does have the ability to archive email to a local (again, on your computer) file that can be viewed and searched much like a mailbox, but only on the computer where the archive file resides.  Windows archive files (called PST files) cannot be shared between computers. 

However, if you use either Outlook for the web or Outlook (both "Classic" and "new") for Mac, your options are much more limited. 

• Outlook for the Web has no archiving ability at all.
• Outlook for Mac can export email to an archive, but that archive cannot be searched - it can ONLY be used to re-import the mail and other items back into a mailbox. That's not particularly helpful.

So if you use Outlook on the web or Outlook (new or classic) on a Mac and are running out of space, what can you do?

For now, the only workable solution that SCS Computing has found is to manually move messages to a secondary (archive) mailbox. In our experience, archiving emails based on their "received" (or "sent") date is the most straightforward (and easy to remember) way to archive messages. 

Moving a small amount of email from 1 folder to an archive mailbox: 

This is fine to do in Outlook on your computer.  Just know that the changes you make are made first locally on the computer, and are sync'ed over time to the server.  So if you make the change in Outlook and shut down your computer, those changes are unlikely to be reflected in Outlook on the Web

Moving a relatively small amount email from multiple folders

If you have a relatively small amount of email to move, but from multiple folders, we recommend using Outlook on the Web,(https://outlook.office.com) as this moves messages directly on the mail server. Moving email between accounts using Outlook on the Web can be done on any computer (Mac, Windows, or Linux) and using any browser (Edge, Chrome, Firefox, etc.). 

Why not use the Outlook client for this? There's a long technical explanation, but the short version is that moving large numbers of email will take at least twice as long if you do it in the Outlook client. Outlook essentially sync's what's on the server (in your mailbox and any shared or archive mailboxes you've added to Outlook) to a local cache file.  So any changes you make are first made to the local file, then Outlook tells the server to make the same changes on the server side.  This means that very copy happens twice. And if you get impatient and start a second move before the first is finished sync'ing, then all sorts of unhappy things can happen up to and including mailbox corruption.   

If you really want to use the Outlook client, then you should move ONE bunch of mail at a time, and wait an hour or so for that move to complete before moving another group of emails.

The Basic Steps to archiving / moving email

1. Go to https://outlook.office.com to log into Outlook on the Web
2. If you have not already done so, add the secondary (archive) mailbox to your Outlook on the Web account. 
   • See Open and use a shared mailbox in Outlook - scroll down to the section titled "Add the shared mailbox so it displays under your primary mailbox"
3. Create the appropriate folder in the archive / secondary mailbox
4. Search for messages
5. Move the messages to the archive mailbox

Create the receiving folder

In the archive mailbox, create a folder with the same name, and in the same location, as the "sending" folder in the mailbox. So, if you're moving messages from a folder called "Project 1" that exists under the "Inbox" folder, then in the archive mailbox, create a folder called "Project 1" under the Inbox.  

Having this already done when moving messages makes that process easier.  It also makes finding archived messages much easier, as the folder structure of the archive mailbox matches the primary mailbox. 

 

Searching for messages by date

1. Open the search filter box: In your mailbox, point your cursor at the right end of the "Search" box, and a small gray box with 3 lines will appear.  
   
   
   
   
2. Click on the gray box and a drop-down window with a number of options for filtering your email will appear:
   
   
    
3. Pick a start and end date by clicking on the first "Select a date" field (and repeating for the end date):
   
   
    
   
   • Initially, the calendar drop-down will show the current month and year, with individual dates in a calendar format.  
   • To change month, you can either:
     • Click on the up (previous month) or down (next month) buttons
     • Click on the month and year text (orange circle), and it will change to show just the current year, with the months listed.  Click on a month to go to the calendar format for that month. 
   • To pick a different year: 
     1. Click on the "month and year" text twice, it will change to show a number of years. 
     2. Click on the year that you want, then on the month, then select the specific date. 
          
4. Search.  When you're finished, click on the blue Search box. 
   
   
5. Expand or limit the search:  You can click on the folder name to the right of the search bar to either limit the search to the current folder or expand the search to all folders. 
   
   
    
   • NOTE: If you thought you limited the search to the current folder but items appear from all folders, it may mean that no matching items were found in the current folder.  If this happens, you may see a message like this (except it won't be circled in red!): 
     
     

Moving messages

Once you have your search done, you'll need to move the messages to the secondary mailbox.   

1. Select the messages to move.   Click on the square next to "All" to select all messages.
   
   
    
   • NOTE:  If there are many messages, Clicking on the "Select all" box all will only select the amount loaded into memory.  If you scroll down, you'll find that the messages or conversations stop being selected at a certain point.  DO NOT SELECT ADDITIONAL MESSAGES or CONVERSATIONS - if you do, the move takes MUCH longer.  You'll just need to repeat this step multiple times to move all of the messages that meet your criteria. 
      
2. Select the receiving folder.  Right-click on any selected message to bring up a menu. 
   1. Select Move from the context menu. 
   2. At the bottom of the menu, you'll see the list of additional mailboxes that have been added to your Outlook.  Click on the archive mailbox. 
      • NOTE: The "Search In" box will change from "Search for a folder" (this indicates that the folders listed are in YOUR mailbox) to "Search in [archive mailbox name]".  
      • If you're in a folder other than a main top-level folder, AND you've made a corresponding folder in the archive mailbox, then the folder you want should appear at the top.  If not, you can select Move to a different folder...
   3. Click on the folder where you want the items to move. 

Depending on how many messages you're moving, and how large they are, the move process can take anywhere from 1-2 seconds to 30 minutes to complete.  

Repeat the process as needed for each folder that you wish to archive.

Advanced - If you need an immediate impact on space

Sometimes, a mailbox has just hit a "milestone" of storage (at 99 GB, you can no longer send email, and at 100 GB, you can no longer send or receive email), and immediate remediation is necessary.  

As in the example above, the larger goal for this exercise is to move ALL email from a particular time period to an archive folder.  But we can make a faster difference by targeting the LARGEST email within that time frame first. 

Target the largest emails - basic steps

1. Figure out which folder(s) contain the most items
2. Create the receiving folder(s)
3. Find the largest items in the largest folders
4. Move individual emails that fall within the time period of email to be moved
   • For instance, if you will be moving ALL email from 1/1/2015 through 12/31/2019, then we'll look for the largest emails from 2015-2019 to move first

What folder(s) have the most storage? 

1. Log into Outlook on the web (https://outlook.office.com)
   • NOTE:  If you are doing this for a mailbox other than your own, you'll need to open that mailbox in a separate window for this step - see Open and use a shared mailbox in Outlook, and scroll down to "Open the shared mailbox in a separate browser window" for instructions.
2. Click on the "Settings" gear icon in the upper right corner
3. Select Account, then Storage
   
   
   
   
4. A list of folders will appear, sorted by size.  Junk Email and Deleted Items are always at the top.  The third folder listed will be the largest in terms of storage, so that's where you should start. 
5. Take a screenshot (Windows or Mac) of the list and paste it into a Word document or a graphics program so you can reference it.
6. You can then close the settings window by clicking on the "X" in the upper right corner

Create the receiving folder

In the archive mailbox, create a folder with the same name, and in the same location, as the "sending" folder in the mailbox. So, if you're moving messages from a folder called "Project 1" that exists under the "Inbox" folder, then in the archive mailbox, create a folder called "Project 1" under the Inbox.  

Having this already done when moving messages makes that process easier.  It also makes finding archived messages much easier, as the folder structure of the archive mailbox matches the primary mailbox. 

Filter for attachments and Sort email by size

1. If you have not already done so, add the secondary (archive) mailbox to your Outlook on the Web account. 
   • See Open and use a shared mailbox in Outlook - scroll down to the section titled "Add the shared mailbox so it displays under your primary mailbox"
2. Go to the biggest folder (remember, this is the 3rd folder in the list, after "Deleted Items" and "Junk Email") in the primary mailbox's folder list
3. Filter for attachments. Click on the "Filter" button, and select Has files - Attachments are what take up the most space in emails
4. Arrange by size, largest on top: Next to the "Filter" icon, you'll see how the email is currently sorted (red circle, below). This will likely read "By Date" - click on this and select By Size
5. Click on By Size again to select the ordering.  In the "Sort order" section, select Largest on top
   1. You should now see that the emails are arranged in groups, based on size.  
      
      

Move individual emails to the archive folder

• Click on the Select icon to the left of "Filter". This will display check boxes that you can click to select individual messages to be moved.
• Look down the list of emails and find emails that fit the time frame that you want to archive. 
  • Example: If you're archiving messages older than 5 years and the current year is 2025, then only select messages from today's date in 2020 and before. 
  • Start with the messages in the "Enormous" and the "Very Large" categories.  Moving just a few messages of this size can make an immediate difference!  
• Select the receiving folder.  Right-click on any selected message to bring up a menu. 
  1. Select Move from the context menu. 
  2. At the bottom of the menu, you'll see the list of additional mailboxes that have been added to your Outlook.  Click on the archive mailbox. 
     • NOTE: The "Search In" box will change from "Search for a folder" (this indicates that the folders listed are in YOUR mailbox) to "Search in [archive mailbox name]".  
     • If you're in a folder other than a main top-level folder, AND you've made a corresponding folder in the archive mailbox, then the folder you want should appear at the top.  If not, you can select Move to a different folder...
  3. Click on the folder where you want the items to move. 

 

Moving LARGE amounts of email

Turns out the best way to move large amounts of email is to use the Windows Outlook client. 

IMPORTANT NOTES: 

1. While this process is going on, the ONLY location of the archived email is the PST on the archiving computer.  And we will need to wait for the archiving process to finish before we start moving mail to the server or the entire process will take FOREVER.  
    
2. The maximum size for a PST is 50 GB.  So plan carefully.  When doing the initial "mailbox cleanup", you may need to do the cleanup into 2 or 3 PST files.  While it may be annoying to have to juggle multiple PST files, Outlook handles smaller PST files better than larger ones.  
    
3. Importing from a PST to the archive mailbox can take a VERY long time.  To shorten the time, it's important to: 
   1. Make each PST no more than 20 GB - preferably closer to 10 GB
   2. Be sure to "compact" the PST before importing - this ensures that all extraneous data is removed (deleted folders, etc.)

Setup

• Setup a temporary machine for this - a loaner laptop works well
• If doing this for someone else:
  • Have them log into the machine.  They'll need to stick around for a bit to get the mailboxes added. 
  • Create a "picture password" - this will let you log into the machine without having to know their password by clicking or drawing shapes on specific parts of the picture. 
    • First, download a picture that you'll use for the picture password.  Pick something with features that you'll remember.  Order of operations is important. 
    • Search for "picture" in the start menu - "Setup a picture password sign in" should appear
    • They'll need to log in
    • Select the picture, then setup the places you'll click or draw on (easiest is to pick 3 places to click)
• Open Outlook on the Web (if you use Edge, it should auto-login, as it just passes your Windows credentials!), but it's still a good thing to do right away with the user there so they can log in if necessary
  • Click on the gear (upper right corner, next to the user's initials), then Account > Storage
  • The top two folders are "Deleted Items" and "Junk Items" regardless of size.  
  • The 3rd folder and onward are sorted by size.  Therefore, whatever folder is listed 3rd is where we'll start for the most impact. 
  • You might want to make a screenshot of at least the top several folders - sort of a "before and after" thing. 

Adding mailboxes and PST (temporary holding spot)

• Add primary mailbox (PriM)
• Add archive mailbox (ArchM) - do not use "offline" mode - this will just take forever to sync mail locally
• Add an archive PST- this will be used as an intermediate step
  • RECOMMENDED:  Name this something like "ARCHIVE-TEMP.PST
  • Remember that a PST is limited to 50 GB

Archiving mail

• File > Tools > Clean Up Old Items...
• Be sure "Archive this folder and all subfolders" is selected
• Select PriM Inbox
  • NOTE:  Do NOT select the top-level of the PriM, or the "calendar" gets archived too.  This is a problem because any recurring meeting requests that began before the date that your archiving from will be REMOVED.  Not good. 
• Put the earliest date that you want to leave in the mailbox
  • For faculty who get a LOT of email, really try to make this as short as possible - recommended is 1/1/[current year]
• Be sure that "Include Items with 'Do no AutoArchive' checked" is selected
• Select the archive PST file created above
• Click OK to start the archiving process
• You'll see "Archiving Inbox" in the Outlook status bar. 
• After a bit, you should start to see the unread count (there's ALWAYS an unread count!) on the PriM Inbox decreasing, and the unread count on the archive PST Inbox increasing
  • This will probably take a LONG time - 12 hours?  Maybe more, maybe less.  We'll see. Depends on just how much of the mailbox is stored in the Inbox. 
  • IMPORTANT NOTE:  While the archiving process is happening, the ONLY place that the mail exists is the PST on the local hard drive.  

Rinse and repeat with other top-level folders!  Since a PST is limited to 50 GB, you may need to create an additional archive PST file! 

• Go back to Outlook on the Web, click the gear, select Account > Storage and you should see a SIGNIFICANT difference from before. 
• Repeat the "Archiving mail" section above, and repeat for the next folder on the list 
  • NOTE:  The new largest folder might be something new - double-check this in Outlook on the web. 

Importing email into the archive mailbox

• First, think about how you want the archive mailbox arranged. Consider breaking a large "Inbox" into several "year" inboxes as subfolders. 
• Create the subfolders you want in the archive mailbox
• Create the same subfolders in the archive PST
• Create a "folder PST" - this is a PST into which you'll move a portion of the "Archive PST" - keep this PST to around 10 GB. 
  
  • IMPORTANT: Name the "folder PST" carefully, so you can easily identify what you'll be moving into it (e.g "archive-2000-2023")
• Create a parent folder structure in the "folder PST" to match the ArchM - this will allow Outlook to simply move messages
  • For example, if you'll be importing to a subfolder of the Inbox, create an "Inbox" folder
• Move the folder(s) to the imported from the Archive PST to the Folder PST.  Verify that the folder structure matches the ArchM.
• Be sure to "compact" the PST files (both the main archive PST and the folder PST) - this is basically a "clean up" process 
  • Compacting the primary archive PST will speed up moving folders to other PSTs - especially once data has been moved out of the PST
  • Compacting the folder PST will speed up the import process dramatically
• Click File > Open & Export, then click on Import / Export
• Select Import from another program or file and click Next
• Select Outlook Data File (.pst) and click Next
• Click Browse and select the "folder PST" that will has the data to be imported.  Select Do not import duplicates.  Click Next
• In the "Import Outlook Data File" window, just leave the "Outlook Data File" (this will be the "root" of the Folder PST) selected.
  • Be sure that Include subfolders is selected (this is selected by default, but always good to check!)
  • VERY IMPORTANT:  In the "Import items into the same folder in" drop-down, be sure to select the ARCHIVE MAILBOX.  The primary mailbox is the default.  If you leave this alone, you'll just undo all of the archiving you've done so far.  
  • Click Finish
• The import process will start.  This will take a LONG time - expect 1 hour/GB to be imported. So, 10 GB = ~10 hours
  • It's good to check on the progress periodically. 
  • NOTE: The green progress bar will reach the end, and then start over. That will happen a lot.  Oh.. and do NOT believe the time remaining.  The process will be over when it's over. 

How to avoid running out of space in the future?

The answer is surprisingly simple:  Stop sending attachments, as attachments are what take up space in an email account.  Rather than sending attachments, do this instead:

• Upload the file to be shared to a cloud storage service such as Google Drive or Box or OneDrive (or create a shared folder)
• Create a link to the shared file or folder
• Send the link in your email

In addition to saving space in your mailbox, sending links to files or folders has a secondary benefit: control.  You can control who has access to the files you share, and what kind of access they have. Nearly all online storage services allow you to specify who has access, or to create a link that will make the file available to anyone with the link. You can also decide if someone can edit the file, download the file, or merely view the file.  And you can also remove access to the shared file at any time.  Once an attachment is sent by email, you lose all control over what the recipient does with the file.  

If you need help creating a shared folder (or something like a Box "Team" folder), contact SCS Computing staff at scs-computing@illinois.edu and we'll be happy to discuss your needs with you.